bluuebunny/crossref_metadata_2025 huggingface dataset:
IMPLEMENTASI INFOGRAFIS PADA VIDEO BASIC MACHINE OPERATION MSP PT. INFINEON TECHNOLOGIES BATAM
Authors: Putri Getha Febriyani , Prasetyaningsih Sandi
Published: May 2021

Sebagai bentuk informasi terhadap proses pengoperasian mesin atau fasilitas untuk menunjang suatu pekerjaan, PT. Infineon Technologies Batam memanfaatkan teknologi multimedia sebagai media penyampaian informasi kepada karyawan agar lebih memahami bagaimana proses pengerjaan dan cara mengoperasikan mesin yang akan digunakan. Multimedia yang digunakan adalah media video yang berisi tentang proses produksi dari industri tersebut. Salah satu video yang akan dihasilkan, yaitu video basic machine operation MSP yang ditargetkan untuk karyawan operator di area MSP (mark, scan, pack), yaitu proses akhir dalam pembuatan produk semikonduktor. Produk yang dihasilkan dalam tugas akhir ini adalah implementasi infografis pada video tersebut, menggunakan metode penyelesaian action research agar video yang disampaikan dapat dipahami dengan cepat dan mudah oleh karyawan PT. Infineon Technologies Batam. Video ini nantinya akan digunakan sebagai salah satu video training kepada karyawan baru untuk mengetahui hal dasar saat bekerja di area produksi, yaitu Alat Pelindung Diri (APD) yang digunakan, Kesehatan dan Keselamatan Kerja (K3), dan flowchart penggabungan motherlot dengan babylot pada proses MSP.
Evaluasi User Experience Game 2D Bajaj Keliling Menggunakan Metode Game Experience Questionnaire
Authors: Joncicilia Nike , Riwinoto Riwinoto
Published: May 2021

Di era digital ini, permainan smartphone menjadi populer bagi semua kalangan. Meskipun jumlah gamers di Indonesia semakin meningkat, tidak menjamin bahwa setiap game memiliki jumlah peminat yang banyak. Setiap industri game berlomba-lomba untuk memiliki user experience yang baik agar para peminat game industri tersebut selalu meningkat. Ini menunjukkan bahwa user experience pada sebuah game sangat penting untuk mendukung kesuksesan sebuah game. Permainan Bajaj Keliling belum pernah melakukan evaluasi user experience sebelumnya. Untuk keberhasilan permainan Bajaj Keliling, maka dari itu perlu dilakukan evaluasi user experience. Setelah dilakukan evaluasi user experience pada permainan Bajaj Keliling, maka akan dilakukan perancangan ulang berdasarkan rekomendasi evaluasi user experience pertama, lalu hasil perancangan ulang permainan Bajaj Keliling akan dievaluasi kembali. Metode yang digunakan untuk evaluasi menggunakan Game Experience Questionnaire, sedangkan untuk proses perancangan menggunakan metode Design Sprint. Setelah dilakukan analisis pertama, hasil menunjukkan bahwa pada Core Module untuk komponen flow bernilai 2.17 dan challenge bernilai 2.21, serta komponen challenge pada In-game Module bernilai 2.22, semua nilai rata-rata tersebut rendah dan berada di bawah median. Hal tersebut menunjukkan bahwa permainan mudah untuk dimainkan dan tidak terlalu menantang. Solusi yang diimplementasikan yaitu mengganti fitur stage menjadi level dan menambahkan tantangan baru berupa pertanyaan pada setiap awal level. Setelah dilakukan evaluasi kedua, hasil pada Core Module untuk komponen flow yaitu 3.17 dan challenge yaitu 3,09, rata-rata menjadi meningkat dan berada di atas median. Hasil dari komponen challenge pada In-game Module juga meningkat menjadi 2.37, namun nilai rata-rata tersebut masih di bawah median.
Keyboard Concertos in E-flat Major and F Minor
Authors: Hertel Johann Wilhelm
Published: May 2021

The works of the German court composer Hertel exemplify transitional stages in the structural and stylistic development of the early Classical concerto. These charming concertos from the third quarter of the eighteenth century are rich in varied patterns of keyboard figuration idiomatic to the pianoforte, the keyboard instrument Hertel preferred.
BIOGRAFI K.H AHMAD ZUHDIANNOOR
Authors: Yusup
Published: May 2021

Negara Indonesia memiliki berbagai wilayah dari sabang sampai marauke. Setiap wilayah yang ada di Indonesia memiliki suatu Provinsi, salah satunya ialah Provinsi Kalimantan Selatan yang memiliki berbanyak para Ulama yang terkenal di kalangan masyarakat. Ulama sendiri ialah orang yang takwa kepada Allah SWT, berilmu agama sangat baik yang memberi bimbingan terhadap kalangan masyarakat kejalan kebaikan. Alhamdulillah di Provinsi Kalimantan memiliki banyak para Ulama yang menjadi suatu pengaruh sangat baik bagi kehidupan. Salah Satu Ulama yang ada di Kalimantan Selatan ialah K.H. Ahmad Zuhdiannoor yang sangat pengaruh besar terhadap kalannagan masyarakat menjadi lebih baik dengan adanya syukur dan sabar
Introduction to The Origin of Electromagnetic Mass (Electromagnetic Inertia)
Authors: Vegt Wim
Published: May 2021

Newton described in his second law of motion the classical definition of mass (inertia). However, it is impossible to calculate with Newton’s second law of motion the (electromagnetic) mass of a beam of light (Ref. [1], [2],[3]). Because the speed of light is a universal constant which follows from Albert Einstein’s Theory of Special Relativity, it is impossible to accelerate or to slow down a beam of light and for that reason it is impossible to determine the electromagnetic mass of a beam of light (free electromagnetic radiation) by Newton’s second law. To calculate the electromagnetic mass of free or confined electromagnetic radiation, the fundamental concept of the New Theory has been used that the Universe is in a perfect Equilibrium and that any electromagnetic field configuration is in a perfect equilibrium with itself and its surrounding. From this fundamental concept follows a different definition of (confined) electromagnetic mass. Electromagnetic mass (or inertia) has been determined by the relativistic Lorentz transformation of the radiation pressures in all different directions and the disturbance of a uniform motion (or position at rest) of confined electromagnetic radiation results in a relativistic effect which we measure (experience) as electromagnetic mass (inertia). The mass in [kg] of an object will be generally measured by acceleration (or deceleration) of the object according Newton’s second law of motion. In the theory of special relativity, the speed of light is a fundamental constant and the intensity of the light is not a universal constant. The calculate the relativistic mass of Confined Electromagnetic Radiation, we start with a thought experiment in which a beam of light is propagating between two 100 % reflecting mirrors, indicated as Mirror A and Mirror B. Both mirrors are part of a rigid construction and the relative velocity between both mirrors always equals zero. The results of this calculation will be generalized for any kind of electromagnetic radiation which has been confined by its own electromagnetic and gravitational field. When the speed of the observer has the same speed as the speed of the light source, then the observer and the light source are relative at rest. And the same light intensity will be measured at the location of the emitter and at the location of the observer.
Differential expression of GSTM5 in cancers of the breast.
Authors: Mamoor Shahan
Published: May 2021

Breast cancer affects women at relatively high frequency (1). We mined published microarray datasets (2, 3) to determine in an unbiased fashion and at the systems level genes most differentially expressed in the primary tumors of patients with breast cancer. We report here significant differential expression of the gene encoding glutathione S-transferase mu 5, GSTM5, when comparing primary tumors of the breast to the tissue of origin, the normal breast. GSTM5 mRNA was present at significantly lower quantities in tumors of the breast as compared to normal breast tissue. Analysis of human survival data revealed that expression of GSTM5 in primary tumors of the breast was correlated with overall survival in patients with basal subtype cancer, demonstrating a relationship between primary tumor expression of a differentially expressed gene and patient survival outcomes influenced by molecular subtype. GSTM5 may be of relevance to initiation, maintenance or progression of cancers of the female breast.
How diverse are the samples used to study intimate relationships? A systematic review
Authors: Williamson Hannah Camille , Bornstein Jerica Xelia , Cantu Veronica , Ciftci Oyku , Farnish Krystan , Schouweiler Megan
Published: May 2021

The social and behavioral sciences have long suffered from a lack of diversity in the samples used to study a broad array of phenomena. In an attempt to move toward a more contextually-informed approach, multiple subfields have undertaken meta-science studies of the diversity and inclusion of underrepresented groups in their body of literature. The current study is a systematic review of the field of relationship science aimed at examining the state of diversity and inclusion in this field. Relationship-focused papers published in five top relationship science journals from 2014-2018 (N = 559 articles, containing 771 unique studies) were reviewed. Studies were coded for research methods (e.g., sample source, dyadic data, observational data, experimental design) and sample characteristics (e.g., age, education, income, race/ethnicity, sexual orientation). Results indicate that the modal participant in a study of romantic relationships is 30 years old, White, American, middle-class, college educated, and involved in a different-sex, same-race relationship. Additionally, only 74 studies (10%) focused on traditionally underrepresented groups (i.e., non-White, low-income, and/or sexual and gender minorities). Findings underscore the need for greater inclusion of underrepresented groups to ensure the validity and credibility of relationship science. We conclude with general recommendations for the field.
Being cut off from social identity resources has shaped loneliness during the COVID-19 pandemic: A longitudinal interview study with medically vulnerable older adults from the United Kingdom
Authors: Harkin Lydia , Stuart Avelie , Stevenson Clifford , Daly Rosie , Talbot Catherine V. , Park Miriam , Katz Dmitri , Sanderson Lisa , Gooch Daniel , Levine Mark , Price Blaine
Published: May 2021

Older adulthood is often a time of identity change arising from physical decline and social isolation which can increase loneliness. These effects are thought to be exacerbated by public health threats such as COVID-19 which disproportionately restrict older adults, though research has yet to fully explore how this occurs. We used a Qualitative Longitudinal Research (QLR) interview approach to follow nine vulnerable older adults (Mage=79.4) for fourteen months through 2019 and 2020 in order to understand their unfolding experiences of pandemic-related isolation. A theoretically guided thematic analysis found that participants initially experienced “Threatened Social Contact” due to age-related vulnerabilities which reduced their ability to manage “Being Categorised as a Vulnerable Older Person”. Consequently, participants experienced a “Restriction in Ability to Gain or Maintain Identities” leading to “Undermining of Reciprocal Support” and “Wellbeing hindered by Loneliness-Related Fears”. Findings highlighted that COVID-19 exacerbates existing negative age-related categorisations, contributing to a loss of reciprocal support in older adulthood. More generally, interventions to ameliorate loneliness among older adults would benefit from explicitly addressing ageism as well as enhancing group-based connectedness.
Aversive Motivation and Cognitive Control
Authors: Yee Debbie Marianne , Leng Xiamin , Shenhav Amitai , Braver Todd Samuel
Published: May 2021

Aversive motivation plays a prominent role in driving individuals to exert cognitive control. However, the complexity of behavioral responses attributed to aversive incentives creates significant challenges for developing a clear understanding of the neural mechanisms of this motivation-control interaction. We review the animal learning, systems neuroscience, and computational literatures to highlight the importance of experimental paradigms that incorporate both motivational context manipulations and mixed motivational components (e.g., bundling of appetitive and aversive incentives). Specifically, we postulate that to understand aversive incentive effects on cognitive control allocation, a critical contextual factor is whether such incentives are associated with negative reinforcement or punishment. We further illustrate how the inclusion of mixed motivational components in experimental paradigms enables increased precision in the measurement of aversive influences on cognitive control. A sharpened experimental and theoretical focus regarding the manipulation and assessment of distinct motivational dimensions promises to advance understanding of the neural, monoaminergic, and computational mechanisms that underlie the interaction of motivation and cognitive control.
Design and Build Customer Complain Applications for Mobile Based MVVM Architecture Method
Authors: Gunawan Alexius Hendra , Wijaya Andri , Wijaya Dellih
Published: May 2021

Abstract

PT. DhanaJaya BogaIndo has more than twenty restaurants spread across Jakarta, Surabaya and Australia. At present complaints regarding services and food served are still being done by providing limited criticism and suggestions during operational hours, so employees in the service section always record complaints and suggestions from customers who come to restaurants are accommodated, then convey related to food, service and the environment dirty one. related to customer complaints. Information on customer complaints can be received directly by management, so actions can be taken quickly.
En torno a las dimensiones del espacio público: el caso de la Ciudad Autónoma de Buenos Aires
Authors: Santaló Claudia Berta
Published: May 2021

En este artículo se indaga en torno a las dimensiones del espacio público reflexionando acerca de las distintas perspectivas desde donde concebir las actuaciones sobre el mismo. Se toma el caso de la Ciudad Autónoma de Buenos Aires donde en los últimos años se han realizado obras necesarias en el espacio público que contribuyen al mejor funcionamiento de la ciudad y al crecimiento de ciertos estándares en la calidad de vida. Sin embargo hoy pareciera ser otra la perspectiva necesaria para entender las prioridades de la ciudadanía.
El espacio público y los centros comerciales
Authors: Chumpitaz Mellarez Felipe
Published: May 2021

Para opinar acerca de una relación entre dos espacios, es importante evaluar el comportamiento de ambos, un hecho que deviene en el análisis de manifestaciones culturales a través del tiempo, la situación actual y, quizás, atreverse a proyectar lo que podría acontecer en el futuro, siempre en términos condicionales, toda vez que lo menos predecible son las tendencias del comportamiento humano. Sobre todo, cuando no existe un plan que lo encamine, porque no se cuenta con los medios y los recursos económicos para llevarlo adelante o por ser este extremadamente complejo por la diversidad y cantidad de factores a tomar en cuenta para su aplicación eficiente.
A Review on Protection from Corrosion, Oxidation and Hot Corrosion by Thermal Spray Coatings
Authors: Tobe S.
Published: May 2021

It is pointed out that properties corresponding to 3 to 5 % of gross domestic products are lost by corrosion in every year in advanced countries. Corrosion including oxidation is still one of the biggest technical problems which human beings are facing. The application of thermal spray coatings is one of the strongest weapons to prevent corrosion of steel and iron structures. The thermal spray coatings, however, are not panaceas to prevent corrosion. They involve many problems and it is important to understand the proper ways to apply the thermal spray coatings for corrosion resistance. In this paper, a state-of-the-art review on the science and technology against corrosion, oxidation and hot corrosion by the thermal spray coatings is presented.
Field Performance of Sprayed Zinc Cathodic Protection Anodes
Authors: Tinnea J.S.
Published: May 2021

The corrosion of steel in the global reinforced concrete infrastructure is at epidemic proportions. The resulting damage is seen in highway bridges, apartments, paper mills and aquariums. In North America reinforcement corrosion in concrete bridges and parking garages generates cost estimates that range from $325 million to $1 billion per year.1 One anode material gaining acceptance is zinc thermal spray (TS) coating. Since the first installation in 1983, zinc TSCP systems have been applied to reinforced concrete bridges, docks, parking garages and even aquariums. This paper discusses the performance of field applications of zinc thermal spray coating CP systems. The systems discussed have sprayed surface areas ranging from 280m2 to 24,000m2 The installations are on major concrete structures. The performance of both galvanic and impressed current systems are discussed.
Thermally Sprayed Composite Coatings for Enhanced Corrosion Protection of Steel Structures
Authors: Lester T. , Kingerley D.J. , Harris S.J. , Matthews S.P.
Published: May 2021

Zinc and aluminium coatings have been used widely to protect steel structures from corrosion in aggressive and hostile conditions. The more recent development of zinc 15wt% aluminium alloy in a wire form has demonstrated that arc-spray coatings can be produced with a resistance to red rust which is superior to that of the single metals. Competitive 'pseudo' alloy or composite coatings produced by co-spraying wires of zinc and aluminium have been shown to achieve resistance to salt spray conditions similar to this conventional alloy. Work described in this paper confirms these findings and goes on to demonstrate an additional advantage of co-spraying an aluminium -5wt% magnesium instead of aluminium with the zinc. The importance of providing a fine dispersion of the two phases in the 'pseudo' alloy is highlighted and an alternative method of providing a similar dispersion by using a 'cored' wire (e.g. Al-5wt%Mg wire in a zinc sheath) approach has been demonstrated. The importance of 'self sealing' in these coatings after the initial loss of zinc is discussed which is related to the coating microstructure and their electrochemical behaviour in chloride solutions.
Corrosion Resistance HVOF Coatings Based upon TiC+NiTi and (Ti,W) C+Ni
Authors: Guilemany J.M. , De Paco J.M. , Miguel J.R. , Sanchez J. , Smith P.
Published: May 2021

The development of new spraying processes has increased the demand for high quality protecive coatings. Many thermal spraying processes have been developed to obtain coatings for a wide spectrum of materials and substrates. The High Velocity Oxygen Fuel (HVOF) process involves lower temperatures and higher velocities than those required by other techniques to obtain high density coatings. It is desirable to know which are the main factors that affect the corrosion behaviour of coated materials. The corrosion behaviour in chloride solution of a 34CrMo4 steel coated with different kinds of powder have been studied. The electrochemical corrosion of the coating-substrate system was characterised by corrosion potential measurements and potentiodynamic polarisations. Microscopic studies have also been performed by means of SEM. The corrosion tests were performed in synthetic marine water (ASTM D-1l41) in the presence of dissolved air. Polarisation resistances have been obtained from potentiodynamic studies. Measurements were carried out on two different (Ti,W)C+Ni coatings, as well as on the coatings obtained from a TiC+Ni-Ti powder which had been previously Ni coated using an electro less method. The best corrosion results were obtained from these last coatings.
An Overview of Alternative Coatings for Wear and Corrosion Resistance
Authors: Tucker R.C.
Published: May 2021

Thermal spray coatings are very effective in combating wear and corrosion in many applications. New thermal spray processes and coating compositions continue to be developed with concomitant improvements in the performance of the coatings and their use in new applications. Nonetheless, the thermal spray coatings are not without competition from other coating and overlay processes and materials. This brief review considers the microstructures and the wear and corrosion resistance of a number of alternative coatings to thermal spray coatings, including physical vapor deposition, chemical vapor deposition, electroplating, autocatalytic, and laser cladding.
Effect of Microstructure and Alloy Additions on the Sliding Friction and Wear of Plasma Sprayed Molybdenum Alloy Coatings
Authors: Usmani S. , Sampath S. , Houck D.L.
Published: May 2021

Molybdenum based thermal spray coatings are used extensively for wear and friction control. However, the sprayed Mo lamellae have been found to have low breakout resistance leading to decreased wear life of these coatings. An alternate approach is to increase the strength of Mo lamellae by alloying them with Mo-C. This work examines the effect of such alloying on the differences in the friction and wear mechanisms of four Mo and Mo-Mo-C based coatings. It was found that alloying the Mo with Mo-C leads to an improvement in the friction behavior of Mo-Mo-C based coatings.
A Review of Clearance Control Wear Mechanisms for Low Temperature Aluminium Silicon Alloys
Authors: Ghasripoor F. , Schmid R.K. , Dorfman M.R. , Russo L.
Published: May 2021

Aluminium silicon alloys have shown favourable properties when used as the matrix for abradable coatings in low pressure compressors of gas turbines [1 and 2]. This paper aims to describe the wear mechanisms found in aluminium silicon based abradables. To this end three thermally sprayed coatings are investigated. Aluminium silicon polyester, aluminium silicon-graphite and the most recently developed, aluminium silicon-hexagonal boron nitride (hBN) examined here are amongst a few of these materials. To be able to design materials to function in as wide a parameter range as possible, a test ng simulating engine mechanisms is required. Tests were conducted using titanium blades at velocities ranging from 250 - 450 m/s, temperatures of ambient to 450°C and controlled incursion rate of 5, 50 and 500 µm/s. The data obtained from these tests is best interpreted in the form of wear maps which characterise the seal performance and therefore are of use to engine and material designers.
A Study in the High Temperature Tribological Characteristics of the Plasma Sprayed ZrO2 Coating
Authors: Song Y.S. , Han J.-C. , Park M.-H. , Ro B.-H. , Lee K.-H. , Byun E.-S. , Sasaki S.
Published: May 2021

The Thermal Barrier Coating (TBC) used to improve the heat barrier and wear resistant property in high temperature of the aircraft engine and the automobile engine, usually has a two layer structure. One is a ceramic top layer for heat insulation and the other is a metal bond layer to facilitate the bond strength between the top ceramic layer and the substrate. But, the coated layers can be peeled off because of the accumulation of the thermal stress by the difference of the thermal expansion coefficient between metal and ceramics in a heat cyclic environment. In this study, the intermediate layer produced by plasma spray process was introduced to reduce the thermal stress. The powders of plasma spray coating were Yttria Stabilized Zirconia (YSZ), Magnesia Stabilized Zirconia (MSZ) and NiCrAIY. The intermediate layer was sprayed with the powders of partially stabilized zirconia with 50wt% NiCrAIY between the ceramics top coat and the bond coat for the purpose of alleviating heat expansion. The high temperature wear and thermal shock test were conducted. The high temperature wear resistance of the YSZ TBC was better than that of the MSZ TBC. The wear resistance decreased with increasing temperature between 400°C to 600°C. The 3 layers TBC with YSZ top coating showed the best thermal shock resistance. This means that the intermediate layer played an important roll to alleviate the difference of the thermal expansion between metallic layer and ceramics layer. SEM and OM were examined. The bond strength, hardness test, and wear test were also studied.
Tribological Properties of Mo/NiCrBSi Thermal Spray Deposits
Authors: Fervel V. , Normand B. , Coddet C. , Delaet M.
Published: May 2021

The tribological behavior of Mo/NiCrBSi coatings obtained by atmospheric plasma spray was studied under dry conditions using an Amsler machine. Discussion is made on the effects of the plasma gas mixture and of the preheating of the substrate. The wear process of Mo/NiCrBSi in situation of dry rolling-sliding contact versus cast iron was observed using a profilometer, an optical microscope, and a scanning electron microscope. It was found that the wear mechanism could be divided into two steps : the first one corresponds to an abrasive wear; it results from the difference in hardness between the counter-specimen and the Mo/NiCrBSi coating. The second one corresponds to an adhesive wear resulting from the transfer of cast iron from the counter-specimen to the coating.
Case Study: Application of HVOF Sprayed Coatings for Replacement of Chrome Plating on Navy P-3 Aircraft Hydraulic Components and Landing Gear
Authors: Parker D.S.
Published: May 2021

Environmental constraints on exposure to hexavalent chrome and its compounds has prompted increased utilization of HVOF thermal spray coating technology to implement new overhaul repairs for components that are currently chrome plated. Proposed 1998 EPA and OSHA standards place very tight restrictions on the Personal Exposure Limit (PEL) for hexavalent chrome, which will impact chrome plating operations and most likely attendant grinding operations. Historically, HVOF or D-gun type repairs involved bearing bores, journals on main shafts, mid span supports, dimensional restorations and clearance control applications predominantly on gas turbine engines. Currently, the Naval Aviation Depot Jacksonville is further developing HVOF capabilities for repairing all P-3 aircraft hydraulic component piston rods, landing gear piston struts, and landing gear axle journals with a tungsten carbide 17% cobalt coating in lieu of chrome plating. Once implemented, the repair technology will be transferred to other Naval aircraft components beginning with F14, F/A-18, EA-6B, E-6, and will eventually reduce personnel exposure to chrome and reduce environmental disposal costs for chrome plating waste by two-thirds. This paper provides a case study of the development and implementation of a chrome plating replacement for the P-3 aircraft including fatigue, corrosion, and seal wear testing, as well as HVOF parameter optimization development.
High Temperature Wear Behavior of Plasma Spray Coating in Co-Based Alloy
Authors: Lee S.W.
Published: May 2021

The tribological behavior of plasma-sprayed coating layers in Co-based alloy was investigated as a function of working distance, gun power, and gas flow. Surface roughness, microhardness, and wear volume were measured for different plasma spraying conditions, wear tests and hardness measurements were conducted at various temperatures, and the cross-section of wear tracks was observed using microscopy. The results obtained shed new light on the high-temperature wear mechanisms of plasma-sprayed coating layers in Co-base alloy.
Modeling of Reactive Spray Atomization and Deposition
Authors: Dai S. , Delplanque J.-P. , Lavernia E.J. , Rangel R.H.
Published: May 2021

Recent experimental investigations of reactive spray deposition of aluminum alloys have indicated that oxides could not be detected for atomization gas oxygen contents lower than 10%. In order to elucidate this behavior, an analysis of the oxidation kinetics during reactive spray deposition based on the Mott-Cabrera theory of oxidation is proposed herein. A linear growth law is obtained that indicates that the oxide growth rate decreases with decreasing temperature or oxygen pressure. Furthermore, the oxide growth rate is found to decrease faster at low oxygen pressure with decreasing temperature as well as at low temperature with decreasing oxygen pressure. Calculations of the width of oxide stringers as a function of oxygen content and superheat temperature based on this analysis are in good agreement with the experimental observations.
Modeling and Diagnostics of the Praxair HVAF Combustion Spray Process
Authors: Varacalle D.J. , Irons G. , Lalumiere R.J. , Swank W.D. , Lagerquist J.
Published: May 2021

The high-velocity air-fuel process (HVAF) is an emerging technology used in the thermal spray industry. The Praxair HVAF process combines air and a liquid fuel (e.g., kerosene, diesel) to generate an energy source with extremely high gas velocities. Analytical studies were conducted to investigate gas and particle dynamics in the Praxair HVAF process for coating with WC-l2Co and stainless steel powders. The mass, momentum, and energy conservation equations were first solved, using the TORCH computer program. Typical output from the model includes temperature and velocity profiles as a function of radial and axial position. The PROCESS gas/particle computer program was then used to calculate from these temperature and velocity profiles the dynamics of particles injected into the gas plume. The primary result of the gas/particle code is a description of the injected particle temperature and velocity as a function of position in the plume. A thorough understanding of the process was obtained using this modeling technique. The results of the modeling were confirmed with process diagnostics. Particle temperature measurements for the WC-Co powder system were obtained with a two-color pyrometer; particle velocity measurements were obtained using particle imaging velocimetry. The coatings produced in the study exhibit superior quality, with high-density, high-hardness, low-oxide content, and high-bond strength.
Finite Elements Modeling of Liquid Particle Impacting onto Flat Substrates
Authors: Feng Z.G. , Montavon G. , Coddet C. , Feng Z.Q. , Domaszewski M.
Published: May 2021

The deformation and spreading of fully molten particles impacting onto a rough surface have been investigated by numerical simulation. A numerical technique, based on finite element analysis, was developed specifically for this simulation. The Lagrangian method with an automatic remeshing technique has been used to trace accurately the free surface of the molten matter and to improve the accuracy of the computation. A friction limiting condition at the particle substrate interface was introduced to describe the effects of the substrate surface roughness. This surface characteristic significantly influences the flattening degree, the flattening time, the spreading velocity of the liquid particle and its final shape.
Numerical Modeling and Simulation of Particle Behaviors in an HVOF Supersonic Flow
Authors: Yang Y.-M. , Coddet C. , Imbert M.
Published: May 2021

Dynamic and thermal behaviors of particles injected into an HVOF supersonic flow were modeled using the Lagrangian formulation coupled with a moving grid system which allows to treat melting and solidification problems in a particle. The particle behaviors of alumina, Tribaloy-400 and MCrAlY were examined by numerical simulations. Velocities calculated by this model were compared with experimental measurements available in publications. For investigating the particle temperatures for which experimental data are hardly available, qualitative experiments were conducted with an MCrAlY powder. It was thus observed that unmelted particles predicted by the numerical simulation were also found in the microstructure of the sprayed MCrAlY coating. From this work, it was shown that the established model provides a reasonable prediction of dynamic and thermal particle behaviors in HVOF flows.
The Features of the Modeling of High-Velocity Pulsating Jets
Authors: Potapenko A.N. , Konstantinov I.S. , El-Hammoudani A. , Semernin A.N.
Published: May 2021

By means of mathematical modelling the features of an outflow of high-velocity pulsating jets out of chambers of gas-detonation installations intended for handling materials are investigated. The boundary value problem is reduced to a solution of an inhomogeneous wave equation with allowance for pressure variation on the boundary of the pulsed source. The calculation of gas-dynamic fields of velocities and pressures is carried out, the volumetric density of potential and kinetic energies and its concentration on the surface under treatment are defined.
Influence of Mechanical and Thermal Behaviour of Stainless Steel Powder Particles During High Velocity Oxy-Fuel (HVOF) Spraying on Properties of Coatings
Authors: Sobolev V.V. , Guilemany J.M. , Martin A.J.
Published: May 2021

Influence of the in-flight behaviour of the stainless steel 316 powder particles during high velocity oxy-fuel (HVOF) spraying on the properties (porosity and level of oxidation) of the coating is studied. Modelling of the in-flight behaviour is undertaken which takes into account the combustion process, gas dynamics, gas-particle interactions, acceleration and deceleration of the gas flow, heat transfer in the particles and full thermal history of the particles including their melting, cooling and the possible solidification. The results obtained are used for the explanation of the experimental data on the coating porosity and level of oxidation.
Modeling and Diagnostics of a New High-Velocity Combustion Wire Spray Process
Authors: Varacalle D.J. , Irons G. , Lalumiere R.J. , Swank W.D. , Lagerquist J.
Published: May 2021

The High-Velocity Combustion Wire Process is a new high-velocity combustion process now being used in the thermal spray industry. This process combines air, oxygen, and a fuel gas to generate a high-temperature, high-velocity plume that is optimum for producing metallic coatings. Analytical studies were conducted to investigate gas and droplet dynamics for the spraying of three different materials: aluminum, stainless steel, and molybdenum. With the relatively low flame temperatures of the process, the feedstock wire is melted by convective heat transfer with no superheating or vaporization of the droplets. When the droplets strike the substrate, their temperature peaks as the high kinetic energy of the droplet is transformed into thermal energy. The conservation equations were solved using the TORCH computer model, yielding the temperature and velocity profiles as a function of location. The PROCESS gas/droplet computer program was then employed to calculate the dynamics of the molten droplets. The results of this modeling was confirmed with process diagnostics. Experimentation included droplet temperature measurements using a two-color pyrometer and droplet velocity measurements using particle imaging velocimetry for the stainless steel material system. The coatings produced in the study exhibit superior quality with high density, high hardness, low oxide content, and high bond strength.
Microstructure and Corrosion Behaviour of HVOF Sprayed Nickel-Based Amorphous/Nanocrystalline Alloys
Authors: Dent A.H. , Horlock A.J. , Harris S.J. , Mccartney D.G.
Published: May 2021

The corrosion characteristics of two bespoke Ni-Cr-Mo-B alloy powders sprayed by the high velocity oxy-fuel (HVOF) process have been studied using potentiodynamic and potentiostatic corrosion analysis in 0.5M H2SO4. The deposits have also been microstructurally characterised using X-ray diffraction (XRD), scanning electron microscopy (utilising both secondary electron (SE) and backscattered electron (BE) modes), and transmission electron microscopy (TEM). Results from the microstructural examination of the two alloys have revealed a predominantly amorphous/nanocrystalline (fcc) matrix containing submicron boride precipitates as well as regions of martensitically transformed laths. Apparent recrystallisation of the amorphous matrix has also been observed in the form of cellular crystals with an fcc structure. The oxide stringers observed at splat boundaries were found to be columnar grained α-Cr2O3, though regions of the spinel oxide NiCr2O4 with a globular morphology were also observed. The coatings of the two alloys exhibited comparable resistance to corrosion in 0.5M H2SO4, as revealed by potentiodynamic tests. They both had rest potentials approximately equal to -300mV(SCE) and passive region current densities of around 1mAcm-2. Microstructural examination of samples tested potentiostatically revealed the prevalence of degradation at splat boundaries, especially those where significant oxidation of the deposit had occurred.
Thermal Spray Quasicrystalline Coatings Part II: Relationships Among Processing, Phase Assemblage, and Tribological Response
Authors: De Palo S. , Usmani S. , Kishi K. , Sampath S. , Sordelet D.J. , Besser M.F.
Published: May 2021

Al-Cu-Fe quasicrystalline coatings, due to their high hardness and low friction coefficients, are potential candidates for improving the wear resistance of ductile materials. However, technological applications may be limited on account of their brittle nature. This study examines the effects of starting powder composition and thermal spray process parameters on the phase assemblage, microstructure, and tribological response of Al-Cu-Fe thermally sprayed coatings. It was found that the coatings fail by a delamination mechanism in unlubricated unidirectional sliding wear. Furthermore, the coatings produced by the high velocity oxy-fuel technique showed a very low coefficient of friction and wear rate.
In Situ Temperature Measurement Using Embedded Micro-Thermocouples in Vacuum Plasma Sprayed Multi-Layered Structures
Authors: Verdy C. , Serio B. , Coddet C.
Published: May 2021

The integration of thermocouples into thermal spray deposits and especially into vacuum thermal spray coatings could provide temperature monitoring between the substrate and the coating or between two different coatings during the spray process and later during post treatments and service life. Thermocouples of 251µm in diameter were made using Chromel and Alumel wires. Electrical insulation was obtained using a ceramic cement. Astroloy and Copper coatings were successfully sprayed over these sensors and the temperature given by an embedded thermocouple was compared to the response of an infrared pyrometer during the spraying process.
Investigations of the Fracture of Composites Matrix-Coating Under Tension
Authors: Panin V.E. , Klimenov V.A. , Panin S.V.
Published: May 2021

Deformation stages and specific features were studied by mesomechanical methods under tension of plasma sprayed coating-steel matrix composites. The effect of coating quality on the deformation of the matrix at the mesolevel was revealed. The results obtained make it possible to predict reliability and durability of this kind of coating and of the entire composite.
Residual Stresses during Coating Generation: Plasma Sprayed Alumina Coating on XC38—Measurements and Calculations
Authors: Leger A.C. , Haddadi A. , Pateyron B. , Delluc G. , Grimaud A. , Nardou F. , Fauchais P.
Published: May 2021

A simplified 1D model has been developed to calculate the temperature-time history of alumina layering splats. The splats were obtained by plasma spraying alumina fused-and-crushed particles onto steel substrates. The model correlates solidification time with splat layer thickness and cooling rate and helps to explain the process of columnar growth, the development of residual stresses, and the effect of quenching and expansion mismatch.
Coatings for Plasma-Facing Components of Nuclear Fusion Devices
Authors: Mallener W. , Rauwald K.H. , Duwe R.
Published: May 2021

Tungsten coatings on copper substrates were produced and subjected to thermal shock loads in an electron beam device. The aim was to minimize the erosion rates thus caused. They are basically dependent on the level and type of porosity. Moreover, material erosion can also be directly influenced by the spraying parameters in coatings with the same relative density. In this connection, the chamber pressure, powder size and spraying distance play a decisive role.
Plasma Sprayed Boron Carbide Coatings as First Wall Material for Laser Fusion Target Chamber
Authors: Bianchi L. , Brelivet P. , Freslon A. , Fornier A. , Cordillot C. , Jequier F. , Schirmann D.
Published: May 2021

The Laser Megajoule (LMJ) is designed to produce, in laboratory, fusion energy with a significant gain. Such an energy could be achieved by imploding a small capsule filled with a DT mixture. Fusion experiments produce a large emission of neutrons, x-rays, laser scattered light and debris which impose a first wall protection for the laser target chamber made of a low Z and refractory material. As boron carbide appeared to be a good candidate, among others, it was decided to evaluate the potentiality of plasma sprayed B4C coatings for this application. This paper deals with the optimization of plasma spraying conditions to build up coatings that satisfy specifications required for the first wall. Coating general properties are presented as well as outgassing performances. Specific x-ray and laser tests were performed to evaluate coating behavior close to real LMJ working conditions.
W and B4C Coatings for Nuclear Fusion Reactors
Authors: Cavasin A. , Brzezinski T. , Grenier S. , Smagorinski M. , Tsantrizos P.
Published: May 2021

The development of nuclear fusion reactors is presently considered to be the only possible answer to the world's increasing demand for energy, while respecting the environment. Nuclear fusion devices may be broadly divided into two main groups with distinctively different characteristics: magnetic confinement fusion (MCF) and inertial confinement fusion (ICF) reactors. Although the two nuclear fusion technologies show similarities in energy levels (as high as 3 J/cm2) and type of environment (high temperature plasmas) to be contained, the materials of choice for the protective shields (first wall in the ICF and deflectors in the MCF) differ significantly. In ICF reactors, multiple laser beams are used to ignite the fuel in single pulses. This process exposes the first wall to microshrapnel, unconverted light, x-rays, and neutrons. B4C is a low Z material that offers high depth x-ray absorption to minimize surface heating, is not activated by neutrons (will not become radioactive), and offers high hardness and vapour temperature. The long term operation envisioned within MCF reactors, where a continuous nuclear fusion of the fuel is sustained within the confinement of a magnetic field, favours the use of high Z materials, such as W, to protect the plasma exposed deflectors. The reason is a lower erosion rate and a shorter ionization distance in the plasma, which favours the redeposition of the sputtered atoms, both resulting in a lower contamination of the plasma. The production of the first wall and the deflector shields using solid B4C and W materials respectively, is obviously unthinkable. However, ProTeC has developed high density coatings for both ICF and MCF nuclear fusion reactors. W coatings with less than 2% porosity have been produced for both, the Tokamac MCF reactor and its Toroid Fueler. The toroid fueler is a plasma generating device designed to accelerate particles and inject them into the centre of the operating fusion reactor in order to refuel. For the application in an ICF reactor, B4C coatings exhibiting porosity levels below 3% with a hardness above 2500 HV have been deposited directly onto Al substrate. Properties such as outgassing, resistance to erosion and shrapnel, and the influence of x-rays have been studied and showed exceptional results.
Hydroxyapatite-Bond Coat Systems for Improved Mechanical and Biological Performance of Hip Implants
Authors: Heimann R.B. , Kurzweg H. , Vu T.A.
Published: May 2021

Bond coats based on bioinert ceramic materials such as titania and zirconia were developed to increase the adhesion strength of the coating system hydroxyapatite/bond coat to Ti6A14V alloy surfaces used for hip endoprostheses and dental root implants. The bond coats improved the adhesion strength, measured by a modified ASTM D3167-76 peel test, by 50 to 100% and also the resorption resistance as determined by in vitro leaching in simulated body fluid (Hank's Balanced Salt Solution, HBSS) for up to 28 days.
Properties of Coated Tools for Improved Performances
Authors: Rosso M. , Bennani A. , Rastrelli R.
Published: May 2021

The degradation of materials, connected to ageing and wear, can be limited by suitable treatments aimed at the increase of surface properties Among the surface modification techniques thermal spraying processes allow a lot of advantages improving the performance and extending the life of materials and components. The convenience for the substitution of nodular cast iron with coated steel for the manufacture of rolls to be employed in a rod mill plant was studied by means of disk on disk wear tests on plain carbon samples coated with the fuse and spray technology, using 7 different type of nickel or cobalt based powders, comparing their wear resistance with the behaviour of nodular cast iron specimens. On the basis of the wear tests, the most promising coating materials were applied to steel rolls and their behaviour and duration on a rod rolling plant were compared with those of nodular cast iron rolls. The rolls coated with nickel based alloy admixed with WC-Co powder reached the best performance, with a duration about 40 % higher than the cast iron ones.
Fe-AI Intermetallic Coating Applications to Thermal Energy Conversion Advanced Systems
Authors: Magnee A. , Offergeld E. , Leroy M. , Lefort A.
Published: May 2021

In many industrial processes, metallic materials are subjected to high temperature corrosion and aggressive forms of erosion. Such conditions occur especially in thermal energy advanced systems using tube bundles of fluidised bed boilers. For these types of plants, availability and low costs determine the choice of materials and in most cases this choice is not optimised for middle or long-term behaviour. Moreover, few data exist to estimate material lifetime under such aggressive conditions. Such is the case for low carbon steel grades which constitute the basic materials for these plants. New FeAl intermetallic alloys have been developed in the framework of a European collaboration, and it has been seen that these materials have good corrosion and erosion resistance properties at high temperature. Heat exchanger tubes in low carbon steel have been coated by thermal-spray then tested in a new industrial plant burning a very poor fuel (coal residues). After 5000 hours of operation in a rich erosive high temperature environment (850-900°C), no significant wear was observed on coated tubes whereas the other tubes, without protection, showed an appreciable diameter reduction.
Obtention and Development of Blends of Powder to Obtain Free-Standing Components Produced by HVOF Spray-Forming
Authors: Guilemany J.M. , De Paco J.M. , Miguel J.R. , Llibre J.
Published: May 2021

The feasibility of using the HVOF process for the thermal spray-forming of free-standing components has been investigated. HVOF spray forming offers a number of potential advantages compared to the established procedure of plasma forming, including increases in component density, and reduction in material decomposition during spraying. Using blends of carbide and superalloy powders in various proportions, HVOF spraying has been successfully used to form free-standing cylinders and cones of various lengths and thicknesses. Microstructural examination of the spray-formed material, using optical microscopy and scanning electron microscopy (SEM), has shown a homogeneous distribution of carbides in the superalloy matrix, with very low levels of porosity. Vickers microhardness has been measured on several sprayed forms. In order to complete the study of the different systems, abrasion (Rubber Wheel Test), friction (Ball on Disk Test) and erosion wear results have been obtained. These wear results have been used in order to evaluate the behaviour of the sprayed samples with a different powder percentage in the blends. Corrosion tests have been done to evaluate the corrosion resistance of the sprayed samples (ASTM D-1411).