bluuebunny/crossref_metadata_2025 huggingface dataset:
Rancang Bangun Program Pengelolaan Aplikasi Website Akademik pada Perguruan Tinggi dan Ilmu Pendidikan Panca Bhakti Pontianak
Authors: Sa'adah Rabiatus , Lailiah Badariatul , Abdillah Ari , Rezki Muhammad
Published: November 2022

Teknologi informasi berkembang begitu pesat dari hari ke hari. Dengan berkembangnya teknologi informasi, banyak fasilitas yang disediakan untuk menyampaikan informasi yang tepat dan akurat. Komputer dan internet merupakan salah satu sarana teknologi informasi yang terus berkembang pesat dan tidak akan pernah ada habisnya. Sekolah Tinggi Ilmu Pendidikan dan Ilmu Pengetahuan Panca Bhakti terletak di Jl. Komodor Yos Sudarso, Pontianak, Kalimantan Barat merupakan salah satu perguruan tinggi bidang pendidikan di Pontianak, berusaha meningkatkan kualitas pelayanan yang dibutuhkan oleh mahasiswa akademik agar dapat diterima dengan cepat dan tepat sehingga kualitas pelayanan memuaskan. Dalam hal ini, bukan hanya kualitas sumber daya manusia yang diperhatikan, namun pemanfaatan teknologi harus diberdayakan agar dapat mempermudah pelayanan yang dibutuhkan. Perancangan sistem kerja ini adalah menginput data mahasiswa, data dosen, dan data nilai mahasiswa. Panca Bhakti Pontianak masih menggunakan notebook sehingga relatif lama dan kurang efektif. Dengan adanya sistem informasi akademik berbasis web ini diharapkan dapat memberikan solusi sebagai solusi dari permasalahan diatas. Sehingga dapat mempermudah kegiatan akademik dalam mendapatkan informasi yang lebih akurat tanpa perlu banyak waktu dan tenaga.
PENGELOLAAN DANA DESA DALAM MENINGKATKAN PEREKONOMIAN MASYARAKAT DI DESA KARYAMUKTI KECAMATAN MOOTILANGO KABUPATEN GORONTALO
Authors: Machmud Joice , Paramata Srihantuti , Pitoy Helmi
Published: November 2022

The objective of research was to determine village fund management in improving communities’ economy at Karyamukti village. The method used qualitative research approach with research type is descriptive. Based on the result obtained the planning process is good because it is carried out in a participatory manner involving the community and social institutions. Likewise, the briefing has gone well. However, the organizational aspect is still not maximal because, the determination of the structure is not in accordance with the educational background and so the supervision aspect is still not running well, because the supervision that has so far been carried out by the BPD is only a formality following the habits.
KONTRIBUSI PAJAK REKLAME DALAM MENUNJANG PENDAPATAN ASLI DAERAH (PAD) DI KABUPATEN GORONTALO
Authors: Lamangida Trisusanti , Aday Nindy Anggriyani
Published: November 2022

In general, tax is one of the sources of state revenue whose purpose is to finance development. Advertisement Tax is a type of tax determined by the region as a component of regional tax revenue. This researchh aims to determine how the advertisement tax contribution in supporting local tax revenue. This is a qualitative approach using time series data and interviews. The results showed that the contribution of the billboard tax in Gorontalo Regency every year in the last 5 years (2015-2019) continued to decline as seen from the achievement of realization. However, it is still able to contribute in supporting the Regional Taxes of Gorontalo Regency each year on average of 3.42 percent of Regional Tax revenue.
PARTISIPASI MASYARAKAT DALAM PROSES PERENCANAAN PEMBANGUNAN DI KELURAHAN BOTU KECAMATAN DUMBO RAYA KOTA GORONTALO
Authors: Lamangida Trisusanti , Ibrahim Hamid
Published: November 2022

This study aims to determine community participation in development planning process in the Botu village. This research uses descriptive qualitative research. Data collection techniques use observation, interviews and determination of documentation using three stages of research, namely planning (compiling), implementing and writing reports. While the validity of the data uses triangulation techniques consisting of source and technique. The results showed that community participation in the development process, namely providing ideas, in the form of labor, and participating in providing land to assist the government in the implementation of development. And there are inhibiting factors in the implementation of development, namely the willingness factor and the leadership factor. Keywords: Community Participation, Development Planning
PENGARUH PERTUMBUHAN EKONOMI, INFLASI, DAN JUMLAH INDUSTRI TERHADAP KESEMPATAN KERJA DI KABUPATEN BONE BOLANGO
Authors: Imbran Harijono H. , Nento Jamal Pratama Putra
Published: November 2022

Economic growth, inflation, and employment are indicators that affect employment opportunities and opportunities. The more job opportunities in an area will be able to have a positive impact on the economy in that area. This study aims to analyze the effect of economic growth, inflation and labor on employment opportunities in Bone Bolango Regency. This study uses a quantitative research approach with a 5-year secondary data base (2015-2019) and by using multiple linear regression analysis.The results showed that based on the results of research tests using multiple linear regression analysis techniques, it can be stated that there is a significant effect of the independent variables, namely economic growth, inflation rate, and employment in Bone Bolango Regency on employment. The multiple regression equation formed is: Y = -5.287 + 2.854X1 – 3.833X2 – 2.019X3 illustrates if there is an influence of economic growth, inflation, and labor on the absorption of labor in Bone Bolango Regency.
REALISASI PENGGUNAAN ALOKASI DANA DESA UNTUK PEMBANGUNAN DESA DI KECAMATAN TELAGA BIRU KABUPATEN GORONTALO (Studi Kasus di Desa Pentadio Timur)
Authors: Machmud Joice
Published: November 2022

This research aims to: determine the extent to which the Realization of Village Fund Allocation Utilization for Village Development in Telaga Biru sub-District, Gorontalo Regency (Case Study in East Pentadio Village). The research method uses a qualitative research approach with a descriptive type of research. The results found that: 1) Village Fund Allocation (ADD) received by the East Pentadio Village Government, Telaga Biru District, Gorontalo Regency was more directed at personnel expenditures, goods and services expenditures and capital expenditures, 2) Utilization of ADD funds on personnel expenditures to finance the fixed income of the village head and village apparatus, allowances for the village head and village apparatus as well as allowances for the BPD and its members, 3) The use of ADD funds in spending on goods and services is more directed towards fulfilling administrative matters, monthly fixed costs as well as official travel and others, and 4) Utilization of ADD funds in capital expenditures is more directed at activities for the acquisition of land and buildings as well as the procurement of office equipment. Keywords: ADD, Usage, Realization
ANALISIS PERAN KOPERASI SIMPAN PINJAM TERHADAP USAHA MIKRO, KECIL DAN MENENGAH (UMKM) DI KABUPATEN GORONTALO (STUDI PADA KSP “SURYA” UMG)
Authors: Mokodompit Nur Eng , Rivai Silvoni
Published: November 2022

This research aims to: determine and analyze the role of Savings and Loan Cooperatives on Micro, Small and Medium Enterprises (MSMEs) in Gorontalo Regency (Study on KSP "SURYA" UMG). The research method uses a quantitative research approach with quantitative descriptive research. The result show that: 1) The role of the UMG Savings and Loan Cooperative "SURYA" provides enormous benefits to help. The members acknowledged that the existence of cooperatives was very helpful to support the business progress of entrepreneurs. With the existence of cooperatives, members can make loans in an easy way and cooperatives have different roles from other institutions because for various reasons, members above cooperative institutions are more in favor of entrepreneurs who have limited capital. The role of the "SURYA" UMG Savings and Loan Cooperative is very beneficial for micro and small entrepreneurs because with the amount of loans given to these entrepreneurs, these entrepreneurs try to take advantage of the loans provided by the cooperative
ANALISIS PERTUMBUHAN EKONOMI DAN DISTRIBUSI PENDAPATAN KABUPATEN BONE BOLANGO
Authors: Imbran Harijono
Published: November 2022

This study aims to analyze the economic growth and income distribution of Bone Bolango Regency. This study uses a descriptive quantitative approach and the data source used is secondary five-year time series data. The analytical tool used is the analysis of economic growth and the Williamson index equation.The results showed that the economic growth of Bone Bolango Regency was very volatile with an average growth of above 6%. The decline was due to low macroeconomic productivity. The results of the Williamson Index analysis show that the average distribution of income in each sub-district is still relatively low. This is evidenced by the index value is still close to 1. The larger the index, the greater the income inequality that occurs.
PEMANFAATAN DANA DESA DALAM MENINGKATKAN PEMBANGUNAN DI DESA HUNTU UTARA KECAMATAN BULANGO SELATAN KABUPATEN BONE BOLANGO
Authors: Mokodompit Nur Eng , Padungge Nazir
Published: November 2022

This study aims to determine how the utilization and use of village funds in improving development in North Huntu Village, South Bulango District, Bone Bolango Regency. This study uses a qualitative approach and uses interview instruments to selected informants.The results of the study concluded that the use of village funds in supporting development in Huntu Utara Bulango Selatan Village had been carried out effectively in achieving village development. The utilization of village funds can be seen from the three indicators studied, namely objectives, financing structure, and community support. These three indicators have been running effectively, therefore the village of North Huntu in the evaluation of the use of village funds is included in the category of not having findings. Thus, the utilization of village funds has been able to increase development in North Huntu Village, South Bulango District, Bone Bolango Regency.
Porosity Characterization and Its Effect on Thermal Properties of APS Sprayed Alumina Coatings
Authors: Tillmann W. , Khalil O. , Abdulgader M.
Published: November 2022

In the present work, three different APS alumina coatings were fabricated using three fused and crushed alumina powders of different particle size fine, medium and coarse. The influence of the particle size on thermal properties and micro-structural features of the produced coating were investigated by thermal insulation test and detailed image analysis technique, respectively. The analyzed micro-structural features include the total porosity, pore size (fine, medium, and large) and cracks. All types of cracks were considered in calculations as voids and were evaluated according to their sizes as pores. All spray parameters except the particle size were fixed throughout the spraying process. The results revealed that the fine starting powder has produced the densest coating with the lowest total porosity and that the total porosity increases with an increasing particle size. This was expected as powders of smaller particle size will reach a higher in-flight temperature and velocity than powders of bigger particle sizes as long as the same spray parameters are applied. However, a detailed image analysis investigation on the three produced coatings showed that the fraction of fine pores and cracks versus the total porosity is substantially higher in coatings produced by using fine starting powders than those produced using medium and coarse powders. In this work, a connection between the thermal insulation and the porosity fraction, which includes fine pores and cracks, was revealed.
New Investigations of the Arc Instabilities in a One-Cathode-One-Anode Plasma Generator Via Special Wavelet-Analysis
Authors: Zimmermann S. , Mudra M. , Bornschlegl O. , Schein S. , Haderer G. , Marques J. , Schein J.
Published: November 2022

Plasma generators are frequently used in a wide field of applications. These applications include thermal coating, plasma-welding, preprocessing of surfaces, sterilization and propulsion systems. The industrial use of plasma generators demands a high level of accuracy and reproducibility which has to be monitored throughout the process. Rather than analyzing results of e.g. a coating process (by electron microscopic) one prefers to have an online assessment of the plasma generator. The plasma generated is defined by various parameters (e.g., temperature, conductivity) which can be measured with suitable measuring systems. Determining all plasma parameters in one setup is very costly and requires a big setup. In industrial facilities it is often suitable to measure one or two physical quantities and derive the plasma parameters from these measurements. This paper focuses on the evaluation of the electric current consumed by the plasma generator and the sound emitted by the whole system. A quick analyzation of these signals - that may result in an online assessment -was accomplished by using the wavelet transform. Multiple experiments were performed to gain reliable and significant data (behavior of the arc/plasma).
Epitaxial Growth During the Rapid Solidification of Plasma-Sprayed Molten TiO2 Splat
Authors: Yao S. , Li C. , Yang G. , Li C.
Published: November 2022

Epitaxial grain growth during the rapid solidification of molten TiO2 in plasma spraying was studied. The crystallographic structure of the TiO2 splats deposited on rutile and α-Al2O3 substrates at 150, 300 and 500 °C was characterized by high resolution transmission electron microscopy and electron back scattering diffraction. The results reveal that homoepitaxial and hetero-epitaxial TiO2 splats can be formed at the deposition temperature of 500 °C. Epitaxial growth is significantly influenced by the crystal orientation. It is easier to form an epitaxial TiO2 splat with a <001> orientation in the direction perpendicular to the substrate surface. In order to explain the formation of epitaxial splat during plasma spraying, a competition mechanism between heterogeneous nucleation and epitaxial growth was proposed. It was indicated that the face (001) of rutile crystal exhibits the largest growth velocity, which is conducive to form an epitaxial splat for the melt with a largest undercooling degree. In addition, the effect of deposition temperature and crystalline orientation on the epitaxy was simulated. The simulation results are in agreement with the experimental observations.
Broken Characteristics of the Oxide Film in Cold Spray
Authors: Xie Y. , Chen C. , Planche M. , Raoelison R. , Verdy C. , Liao H.
Published: November 2022

In cold spraying, oxide-free interface is an important factor for fresh metal bonding between particles and substrate, which determines the bonding strength and final coating quality. In this study, a well-designed experiment was performed to examine the deformation behaviour of the oxide film on copper alloy particle surface after deposition. The experiment results show that partial oxide film could be disrupted during the high-speed impact. However, most of the oxide films were found to remain intact after particle deposition, which limited the exposure of oxide free interface. The presence of oxide film at the interfaces between deposited particles and substrate seriously affected the metallurgical bonding. Besides, substrate material is found to have a strong influence on the deformation behaviour and final state of the oxide film. The study also demonstrated that the bonding mode between deposited particle and substrate strongly depends on the type of substrate.
Partial Repair of Thermally Sprayed and Sealed Corrosion Protection – Organic Coating Material or Thermal Spraying?
Authors: Wilhelm T. , Klesen C. , Maghet T.
Published: November 2022

For many decades thermally sprayed corrosion protection systems on the basis of ZnAl or Al carry out their service for structures in coastal areas, the offshore sector, as CUI (Corrosion Protection under insulation) or anywhere where the properties of thermally sprayed corrosion protection systems bring important advantages in terms of durability. A thermally sprayed corrosion protection system is about to protect the structure 25 to 30 years against corrosion. During this time it may be damaged due to factors like construction work, improper handling or simple aging. There are many standards and regulations, which describe the initial design of thermal spray systems, however they remain silent regarding repair. In particular, a mending of partial regions is hardly described. Specific repair instructions are rare and if present, they differ from one another. Overall there is a lack of knowledge of the proper procedures for partially repairing thermal spraying systems. This project was concerned with tangible corrosion-technical issues of the coating repairs: How does the critical overlap area perform? Have organic coatings benefits? To what extent does a renewed damage affect the lifetime? The aim of the study was to develop practice-relevant instructions for the repair of thermally sprayed duplex systems.
Improvements of Coating Properties and Residual Stress States in Arc Sprayed Aluminium Bronze Coatings by Using an Alternative Gas Mixture
Authors: Hauer M. , Krebs S. , Krömmer W. , Henkel K.-M.
Published: November 2022

The highly cavitation erosion resistant propeller alloys CuAl9Ni5Fe4Mn and CuMn13Al8Fe3Ni2 were arc sprayed with different traverse speeds by using a mixture of nitrogen and 2 % of hydrogen as atomising gas. Residual stresses were measured by the modified hole-drilling method using ESPI. Microstructural, chemical and mechanical analyses were realised to examine adhesive and cohesive properties. Additionally, the cavitation erosion behaviour was investigated. In comparison to coatings sprayed with pressurised air, the results of the study show superior coating qualities with regard to microstructure, cavitation erosion resistance and residual stresses.
A New Technology for Spraying Advanced Low-Temperature (300 ~ 600 °C) Solid Oxide Fuel Cells
Authors: Yuan K. , Yu Y. , Lu X. , Ji X. , Zhu B.
Published: November 2022

Solid oxide fuel cell (SOFC) has been developed for a hundred year and met a great challenge on material design and marketing. In recent years, new SOFC materials are dug up to achieve high energy-output performance at lower working temperature (300~600 °C), namely low-temperature SOFC (LTSOFC). In this study, Ni-Co-Al-Li oxide (NCAL) was used for making dense, thin and uniform coatings on grooved bipolar electrode substrate for LTSOFC. Low-pressure plasma spray (LPPS) technology was applied to manufacture the NCAL coatings. The performance of a fuel cell package using the coated bipolars was tested between 350 and 600 °C, showing 6~8 W power output with 4 single fuel cells (active area of 25 cm2). The LPPS technology is believed to be one of the ultimate ways for manufacturing the thin film/coatings for SOFC applications in future.
The Protection Against Spray Wear Using Pseudoalloys Applied with the Method of Spraying
Authors: Winkelmann R. , Pokhmurska H.
Published: November 2022

An important parameter that affects the protection from wear and tear, is the geometric structure of the abrasive causing the destruction. The equivalent diameter of the particles of the primary influence on protection from wear and tear must be greater than the width of the particle of the crushed abrasive. Here also belongs the requirement for the distribution of the particles inside the matrix was more uniform and dense. The use of solid materials gives this possibility only in the certain circumstances, therefore, it is necessary to use pseudoalloys. Pseudoalloys can be obtained by means of thermomechanical processing of the conventional layers deposited by means of spraying. The particles of the solid material charged with kinetic energy are applied to the heated layers, and they penetrate into inside. Under the influence of the heat energy inside the layers suitable for this, the additional reaction between the substrate and the layer takes place, thus improving the adhesion of the layers. The appropriate regulations were developed, and the reproducible stratification appeared caused by spraying, that is pseudoalloys. A positive consequence of the inclusion of the particles of a solid ceramic material into the spayed layer is the emergence of the current when compressed. The result of the research of the parameters are the optimal performance indexes, optimization criterion served as an indicator of the intensity of the wear. Manufactured pseudoalloys underwent checking in terms of spray wear. The study of spray wear was carried out at the temperatures up to 750 ° C and speed load amounted to 37.5 m/s. The silica sand fractions + 150-212 µm was used as an abrasive. As the covering material the alloys based on aluminum were used. In the places of transition to the substrate the multiphase alloys of the system Fe-Al are formed. It is advisable to use layers with a high iron content to prevent the loose and destruction.
Characteristics of Dense AI2O3 Coating Prepared by Suspension Plasma Spraying
Authors: Ibe H. , Masuda T. , Sato K. , Kato N.
Published: November 2022

Sintering ceramics have been widely used in industries which require electrical and mechanical properties. Thermal sprayed ceramics coatings are also applied for the industries, however the coating which has micron size pores are limited their applications due to inferior electrical and mechanical properties compared with sintering bulk. To expand thermal sprayed ceramics coating applications, dense coatings prepared by suspension plasma spraying are widely studied. Dense Al2O3 coatings are applicable to fabricating equipment for electronics devices, such as ESC. There are no reports regarding electric properties of plasma sprayed dense Al2O3 coating with different spray conditions. In this study to achieve a electric properties of dense Al2O3 coating, spray parameters such as plasma power, gas flow rate and spray distance are investigated. Suspension materials prepared with three microns Al2O3 powder are sprayed by high power suspension plasma spraying system. Spray conditions, plasma power, gas flow rate, and stand-off distance affect the coating density, crystal phase, and mechanical and electrical properties. Mechanism of coating formation by plasma spraying with fine powder suspensions will be discussed based on the findings. Al2O3 coatings obtained by the plasma spraying is applied for application to application utilizing the electrical insulation properties of such electronics devise manufacturing equipment components is proceeding.
Twin Wire Arc Torch with Optimized Flow Parameters
Authors: Farrokhpanah A. , Pershin L. , Mostaghimi J.
Published: November 2022

Wire arc is an effective and affordable type of coating process. Detailed understanding of it helps improving design and optimization of currently available guns. In wire arc process, an arc forming between two charged wires generates enough heat to melt the metallic wires. Blow of air at high velocity over this bath of molten metal leads to atomization. The formed droplets are then accelerated towards the substrate where they impact and solidify during the coating process. The current work is a follow up to our earlier numerical study where numerical simulation of wire arc spraying using ANSYS FLUENT revealed flow circulations inside the gun can affect flow pattern and contribute to energy dissipation. In this study, an attempt has been made to validate and measure this matter using experimental procedures and to seek potential ways of improvement.
Development of Novel Fe-Based Coating Systems for Internal Combustion Engines
Authors: Bobzin K. , Öte M. , Königstein T. , Dröder K. , Hoffmeister H. W. , Mahlfeld G. , Schläfer T.
Published: November 2022

Nowadays combustion engines are the most common way to impel vehicles. Thereby losses occur, due to cooling, exhaust gas and friction. Modern engines roughly dissipate 8% of the chemical energy stored in the fuel because of friction in different tribological systems. The highest potentials for optimisation can be found in the tribological system of inner surface of combustion chamber and piston ring. Besides friction, corrosive stress of inner surface of combustion chamber increases e.g. due to the utilization of auxiliary systems such as Exhaust-Gas-Recovery. In order to save energy, reduce emissions and enhance the lifetime of combustion engines innovative coating material systems need to be developed, especially for inner surface of combustion chamber. This study focuses on the development of innovative iron based materials for combustion chamber application using Plasma Transferred Wire Arc (PTWA) and Rotating Single Wire Arc (RSW) technologies. In order to improve the wear and corrosion resistance boron and chromium are added into the feedstock material. After deposition, different honing topographies are manufactured in order to evaluate their influence on the tribological behavior. Furthermore, electro-chemical corrosion tests are conducted by using an electrolyte simulating the exhaust gas concentrate. In conclusion an optimised coating material deposited by PTWA and RSW and improved surface topographies can be combined.
Significance of Personnel Qualification and Quality Management for Thermal Spray Plants
Authors: Cramer H. , Huber R. , Ohliger-Volmer A.
Published: November 2022

Well-trained personnel is decisive for a successful company. International business relations are increasingly demanding internationally recognised qualification and certification measures. The requirements are stringent particularly in sensitive fields, e.g. aviation and rail vehicles. No matter whether in aircraft engines, power station engineering or the printing and paper industries, numerous requirements on coatings are solved with the aid of thermal spraying. However, in order to be able to master what the language in standards calls a "special process" (i.e. a process whose final result can be checked by means of non-destructive testing to a limited extent only), there is a need for calibrated and monitored installations and parameters as well as for correspondingly experienced, trained and certified personnel. Frequently, ETSSs, ETSs as well as the qualification tests according to ISO 14918 are already integral constituents of contracts relating to thermal spraying (requirement of the German Railways according to DIN 27201-10). The article provides detailed information about training and qualification as well as about the certification of plants and personnel in the field of thermal spraying. Not only the significance of a quality management system but also the particular advantages of the GTS certification are highlighted in this respect.
Effect of Ball Milling of Al2O3 Particle Deposition Behavior on Polycarbonate Substrate Using Vacuum Kinetic Spray
Authors: Kwon H. , Park H. , Lee C.
Published: November 2022

In this study, ball-milled Al2O3 powder was used as a feedstock material for vacuum kinetic spray to deposit hard ceramic Al2O3 coating on a relatively soft polycarbonate substrate. Microstructural and X-ray diffraction analysis of powders and coatings were performed. The results shows that the ball-milled powder has more unstable state than the primary powder. Compared to primary Al2O3 coating the crystallite size and coating thickness of ball-milled Al2O3 coating are smaller and thicker, respectively. Since the ball-milled Al2O3 particles are more easily fragmented during the VKS coating process, it is possible to deposit hard Al2O3 coating on the soft polycarbonate substrate.
Microstructural Characteristics and Performances of C2O3 and Cr2O3-15%TiO2 S-HVOF-Coatings Obtained from Water-Based Suspensions
Authors: Toma F. , Kulissa N. , Langner S. , Potthoff A. , Barbosa M. , Leyens C.
Published: November 2022

Cr2O3 coatings and Cr2O3-based binary coatings offer high hardness, excellent sliding wear performance and corrosion resistance. Therefore, they are widely applied in the paper and textile industry, as well as for pumps and mechanical sealing systems. Compared to the conventional spray processes, the technology of Suspension-HVOF (high velocity oxy-fuel flame spraying of suspensions, S-HVOF) using submicron-scaled raw materials allows the production of dense, finely-structured coatings with smooth surfaces and improved mechanical properties. This work investigates the microstructure and performance of Cr2O3 and Cr2O3-15wt.%TiO2 coatings obtained by SHVOF with water-based suspensions. For the development of the binary composition two routes were used to produce ready-to-spray suspensions: i) dispersion of an appropriate alloyed material in the solvent and ii) mixture of two stable suspensions in the desired ratio. In order to evaluate the potential of suspension spraying over the conventional APS and HVOF processes, the mechanical properties and the corrosion resistance of the S-HVOF Cr2O3 and 85Cr2O3/15TiO2 coatings were compared with the coatings produced from spray powders. From the experimental results it was observed that the suspension sprayed coatings showed in most of cases denser microstructure, good mechanical properties and superior corrosion performances.
Numerical Investigation of the Melting Degree of Ceramic Powder Particles During Air Plasma Spraying
Authors: Bobzin K. , Öte M. , Knoch M. A. , Alkhasli I.
Published: November 2022

Air plasma spraying is a variation of thermal spraying that is used, among others, for the production of thermal barrier and wear resistant coatings. High plasma temperatures enable the processing of ceramic powder particles which have a high melting point and cannot be processed otherwise. Due to their low heat conductance, the ceramic particles are not necessarily fully melted during their flight in the free jet and prior to the impact on the substrate surface. Experimental particle temperature measurements by means of particle diagnostics systems deliver merely the surface temperature of the particles while the melting degree of the ceramic particles remains unknown. Therefore, the temperature field within spherical Al2O3 particles is numerically investigated for a commonly used particle size distribution by considering different particle sizes. The model includes a two-way coupled particle-laden free jet model and takes the latent heat of melting and evaporation into account. The effect of the particles size as well as the stand-off distance on the melting degrees of the particles in the given powder size distribution is determined.
Mechanical Properties of Yttria-Stabilised-Zirconia for Thermal Barrier Coating Systems: Effects of Testing Procedure and Thermal Aging
Authors: Planques P. , Vidal V. , Lours P. , Proton V. , Crabos F. , Huez J. , Viguier B.
Published: November 2022

Cyclic oxidation failure of Atmospheric Plasma Sprayed Thermal Barrier Coatings systems (APS TBCs), commonly used to insulate hot sections in gas turbines, usually results from the spallation of the ceramic top coat. Consequently, in order to predict such spalling phenomena, understanding the mechanisms for cracks initiation and propagation in thermal barrier coatings is of utmost concern for engine-makers. Failure of the TBC is strongly related to the thermal and mechanical properties of each component of the multi-materials system (substrate, bond coat and ceramic) but also to the response of the TBC as a whole. The purpose of the work is to assess the mechanical behaviour of thick TBC using experimental approach for TBC standard lamellar, porous and microcracked microstructure (classically obtained through APS coatings). The experimental characterisation of the mechanical behaviour of the ceramic top coat of the TBC is addressed on specifically designed and prepared free-standing specimens using three points bending (3PB) tests and Small Punch Testing (SPT). The tests are performed on free-standing top coats made of YSZ in the as deposited states and for specimens that undergone isothermal aging at 1100°C for various durations (1h, 10h and 100h). The results of test performed at room temperature using both mechanical testing techniques are compared. This allows to show the evolution of mechanical properties after thermal aging. Tests performed at 850°C in the SPT ring show that the evolution of properties resulting from this aging may be different at room temperature as compare to 850°C.
Porosity Measurements on Heat Treated Suspension Plasma Sprayed YSZ Coatings Using NMR Cryoporometry
Authors: Ekberg J. , Klement U. , Creci S. , Nordstierna L.
Published: November 2022

Suspension plasma sprayed (SPS) coatings can be produced with fine powder particles and tailor-made porosity. This allows to achieve low thermal conductivity which makes the coatings attractive as e.g. topcoats in thermal barrier coatings (TBCs). Used in gas turbine applications, the TBCs are exposed to high temperatures which leads to alterations of the microstructure. To obtain coatings with optimized properties, possible microstructure alterations like closing of pores and opening of cracks have to be taken into account. Hence, in this study, TBC topcoats consisting of 8 wt.% yttria-stabilized zirconia (YSZ) were heat treated in air at 1150°C and thereafter investigated using scanning electron microscopy, X-ray diffraction, and nuclear magnetic resonance (NMR) cryoporometry. For all investigated samples, the porosity decreased as a result of the heat treatment. The finer pores and cracks disappeared and the larger pores grew slightly and achieved a more distinct shape as the material seemed to become more compact.
Microscale Adhesion Strength Evaluation of Cold Sprayed Copper Deposit
Authors: Ichikawa Y. , Tokoro R. , Ogawa K.
Published: November 2022

Adhesion strength is one of the most important characteristics when discussing the reliability of a cold spray. A focused ion beam (FIB) was used to conduct ultra-micro tensile tests for micro-scale adhesive strength evaluations of high-pressure type cold-sprayed copper deposition on an aluminum substrate. It was also used to determine the essential factor of adhesion strength and the coating formation mechanism. The micro-scale local adhesion strength of cold-sprayed copper deposits on an aluminum substrate was successfully evaluated by FIB microtensile tests. The average local adhesion strength of this deposit was 223 MPa. The variations in adhesion strength between deposit and substrate were smaller than the interfacial strength of cold-sprayed deposits. This was caused by the repeated collision of these subsequent particles.
Development of HVAF-Sprayed Novel Fe-Based Coatings for Large Area Applications
Authors: Bobzin K. , Öte M. , Knoch M.A. , Sommer J.
Published: November 2022

One important trend in thermal spraying is the application of novel Fe-based corrosion/wear protection coating systems. A typical field of application for such corrosion and abrasive wear protection coatings are rotary dryers of paper machines. At the moment, these cylinders are coated by wire arc spraying. A disadvantage of the wire arc sprayed coatings is their high thickness, which has a heat-insulation effect, and their high roughness. Therefore, an expensive post production grinding process is necessary in order to achieve the required surface quality. The goal is to develop a HVAF process that enables the production of thin, dense and near net shape corrosion/wear protection coating systems, which significantly reduce the post-production time and costs. In this study, the HVAF coating process and a novel Fe-based feedstock material are investigated. In the first step the Fe-based powder is analysed thermally using differential scanning calorimetry, to investigate the solidification and melting temperature of the feedstock material. Furthermore, the influence of the spraying distance and the powder feed rate on the microstructure and porosity of the resulting coatings is investigated using light microscopy. Furthermore, the deposition efficiency of HVAF coatings is analysed regarding their economic efficiency.
Development of HVAF ID Coating Technology and Materials
Authors: Verstak A. , Gries B. , Breitsameter M.
Published: November 2022

The HVAF process provides a slightly different (to HVOF and other thermal spray processes) and unique combination of thermal and kinetic energy, which presents a technical challenge to material manufacturers who have over the past years optimized their material offerings to the demands and characteristics of plasma, combustion and more recently the various HVOF processes. The recent development of HVAF ID torches, capable of applying the highest quality coatings into dimensions of less than 100mm (4”), has provided a further need to optimize spray materials for the best possible interaction between the spray device and the feedstock in order to meet developing coating specifications from various industries. This paper will discuss the methodologies utilized from the points of view of torch design, material manufacture, spray parameter and procedure optimization, as a means of producing the highest performing coatings to meet specific industry aspirations.
Practical Experiences Using HVOF Sprayed Tungsten Carbide Coatings in the Plastic Foil Industry
Authors: Brandt O. , Möhwald K. , Reimche W. , Bruchwald O.
Published: November 2022

For most HVOF sprayed tungsten carbide coatings powders with identical particle-size distributions and compositions are interchangeable, within the meaning that as long as the manufacturing process is identical other properties are nearly irrelevant. In plastic foil industry often complex strains occur on the surfaces of the used tools. These strains comprises from a chemical attack by means of released process gases due to the thermal conditions and from an abrasive component caused by additives of the plastic. Shaping calender rolls with a high gloss mirror finished surface may show only a minimal wear in such complex strains because otherwise the quality of the foil is affected in a negative way. In this range of applications the practical experience shows that with commercial characterization values such as microhardness and porosity HVOF sprayed tungsten carbide coatings are not sufficiently described. The article describes the effects of different microstructures on the application behaviour of a coating. For that purpose analytical methods such as quantitative phase analysis due to X-ray diffraction by means of Topas-Rietveld-Method were used. Preliminary results of the use of a novel high frequency eddy current test method suggest the potential to allow a local correlation of specific properties of the coatings with their microstructure.
Tribological Behaviour of Flame-Sprayed HDPE/Cu Composite Coatings
Authors: Xu Y. , Liu Y. , Jia Z. , Suo X. , Li H.
Published: November 2022

Electroless plating was employed for making copper (Cu)-high density polyethylene (HDPE) core-shell particles for following coating deposition by flame spraying. Our previous works already reported large-scale fabrication of HDPE/Cu composite coatings against corrosion, biofouling and ageing for marine applications. In this work, we further investigated tribological behaviours of the HDPE and the HDPE/Cu composite coatings. The structure of the composite coatings was designed via controlling the thickness of the copper shell coated on the composite powder. The result shows that the addition of copper slightly decreased the anti-wear property of the composite coating. The tribology mechanisms of the composite coating and the HDPE coating were discussed.
Iron-Based Hardfacing Alloys for Abrasive and Impact Wear
Authors: Maroli B. , Dizdar S. , Bengtsson S.
Published: November 2022

Iron-based hardfacing alloys are widely used to counteract abrasive and impact wear of industrial components soil in, sand and mineral processing applications. These alloys show a high performance to cost ratio as well as a low environmental impact. The wear resistance of the components hardfaced with these alloys depends on achieved coating microstructure i.e. on the alloys chemical composition, the coating method and process parameters selected. The present work focuses on iron based hardfacing alloys with varying amount of chromium, vanadium, tungsten, molybdenum, boron and carbon deposited by plasma transferred arc (PTA) overlay welding. Weldability, hardness, abrasive and impact wear of the overlays are presented and interpreted through their microstructure. The performance of the iron based overlays is compared with that of nickel-based metal matrix composite coatings with tungsten carbide (MMC) commonly used for hardfacing of parts subjected to severe abrasive wear. The hardness of the iron based overlays investigated ranges between 60 and 65 HRC while abrasive wear is typically below 20 mm3 (ASTM G65, procedure A). Microstructure consists of different primary precipitated carbides or borides, a martensitic matrix and eutectic structures.
Advanced Processes and System Technology for High-Performance Laser Cladding
Authors: Nowotny S. , Hillig H. , Kubisch F. , Toma F. , Leyens C.
Published: November 2022

Laser cladding technology is widely used in industry to precisely apply tailored surface coatings, as well as three-dimensional deposits for repair and additive layer-by-layer fabrication of metallic parts. However, the processing of larger components, like tools for oil and gas production, is economically challenging due to the conventionally low deposition rates. Consequently, industry is requesting more powerful technologies that maintain the quality advantages of the laser technology, but also make the process more productive and time effective. The modern highest power diode lasers offer practical solutions for applying of large-area laser cladding with significantly increased productivity. Using a fiber-coupled diode laser of 20 kW power and the accordingly developed laser cladding heads, real deposition rates of metal alloys, e.g. Inconel 625, could reach 14 kg/h. With the new-developed powder nozzles with rectangular profile of the powder jet allows at a laser power of 20 kW single tracks with 45 mm-width can be produced. Besides the laser source, the processing laser head is the key parameter for a high productivity and efficiency of the whole cladding procedure. The paper presents a new generation of high-performance laser cladding heads with integrated process sensors, which guarantee a stable long-time operation at highest power levels. The deposition rates achieved with this technology are equal or even exceed typical values of the common PTA technique. Current applications are large-area coatings on power plant components, hydraulic cylinders for off-shore equipment, and large metal forming tools for automotive bodies.
Alloyed Carbides Beyond WC as a New Material Platform for Solving Challenges in Hardfacing
Authors: Fiala P. , Hepp R. , Zikin A.
Published: November 2022

Tungsten carbide in nickel based self-fluxing alloy overlays has been dominating hardfacing applications due to its excellent properties, namely extremely high wear resistance. Nevertheless, there are still applications and limits which tungsten carbide has not conquered. This study focuses on (TiW)C1-x which was deposited with several matrix materials and tested in wear, corrosion and impact resistance and benchmarked against tungsten carbide. Results for several other carbides such as (NbW)C1-x, (VW)C1-x, NbC1-x and TiC1-x overlays deposited by plasma transferred arc (PTA) and laser cladding (LC) will be presented and discussed. As a result of deposition trials and overlay testing, it was found that better thermodynamic stability of alloyed carbides allows them to be used in an iron based matrix and/or a matrix with a high chromium content, in applications requiring improved corrosion and oxidation resistance, better impact resistance and lower weight.
Understanding the Infiltration Behaviour of Sealers Into Thermally Sprayed Coatings
Authors: Bobzin K. , Öte M. , Knoch M. A. , Kunde C. , Dettloff P.
Published: November 2022

Sealants are widely used in order to enhance the performance of porous thermally sprayed coatings, e.g. for electrical insulation or corrosion protection. In order to accomplish required properties, a good infiltration is necessary. The methods to assess the success of a sealing often rely on determining the infiltration depth by SEM or adding colour pigments to the sealer. In this study, a new approach for assessing the success of a sealing operation is investigated. The underlying assumption is that porous coatings are not gas-tight and by sealing them, the measurable gas flow can be reduced. Therefore, the success of a sealing operation may be assessed by comparing gas flows at defined conditions prior and subsequent to sealing. This hypothesis is investigated by coating special highly porous substrates with a wide range of coating porosities and thicknesses, sealing these coatings, comparing nitrogen flows at a defined pressure prior and subsequent to the sealing operation and correlating the measured changes of nitrogen flow with traditionally assessed infiltration depth and filling degree.
Isothermal Oxidation Behavior of HVAF-Sprayed NiCoCrAlY Coatings: Effect of Surface Treatment
Authors: Zhang P. , Sadeghimeresht E. , Peng R. , Li X. , Markocsan N. , Joshi S. , Johansson S.
Published: November 2022

NiCoCrAlY coatings are widely used as bond coats for ceramic thermal barrier coatings (TBCs) and oxidation and corrosion protective overlay coatings in industrial gas turbines. High temperature oxidation behaviour of NiCoCrAlYs has a great influence on the coating performance and lifetime of TBCs. A promising route to decrease the oxidation rate of such coatings is post-coating surface modification which can facilitate formation of a uniform alumina scale with a considerably slower growth rate compared to the as-sprayed coatings. In this work, the effect of surface treatment by means of shot peening and laser surface melting (LSM) on the oxidation resistance of high velocity air-fuel (HVAF) sprayed NiCoCrAlY coatings was studied. Isothermal oxidation was carried out at 1000 °C for 1000h. Results showed that the rough surface of as-sprayed HVAF sprayed coatings was significantly changed after shot peening and LSM treatment, with a compact and smooth appearance. After the exposure, the oxide scales formed on surface-treated NiCoCrAlY coatings showed different morphology and growth rate compared to those formed on as-sprayed coating surface. The oxidation behaviour of surface treated HVAF-sprayed NiCoCrAlY coatings were revealed and discussed.
Heat Treatment of the Thermally Sprayed Coating System NiCrSi/NiCoCrAlY/Al for Repair Brazing High Pressure Turbine Blades
Authors: Nicolaus M. , Möhwald K. , Maier H. J.
Published: November 2022

Depending on the size and type defects of nickel-based alloy turbine blades two procedures are used mainly: cladding and high temperature brazing. The repair brazing of turbine blades is used to regenerate cracks and surface defects and is the focus of this work. In this contribution a two stage hybrid repair brazing process is presented which allows reducing the current process chain for repair brazing turbine blades. In the first stage of this process the filler metal (NiCrSi) then the hot gas corrosion protective coating (NiCoCrAlY) and finally the aluminium are applied in this order by atmospheric plasma spraying. In the second stage of this hybrid technology the applied coating system undergoes a heat treatment in which brazing and aluminising are combined. The temperature-time regime has an influence on the microstructure of the coating which is investigated in this work.