bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of Oxidation and Microstructures of Warm-Sprayed and Cold-Sprayed Titanium Coatings
Authors: Kim K. H. , Kuroda S. , Watanabe M. , Huang R. , Fukanuma H. , Katanoda H. 
Published: November 2022

Abstract
Thick titanium coatings were prepared by warm spraying (WS) and cold spraying (CS) process to investigate the oxidation and microstructure of the coating layers. Prior to the coating formations, the temperature and velocity of in-flight titanium powder particle were numerically calculated. Significant oxidation occurred in WS process using higher gas temperature conditions with low nitrogen flow rate, which is mixed to the flame jet of an HVOF spray gun in order to control the temperature of the propellant gas. Oxidation, however, decreased strikingly as the nitrogen flow rate increased. In CS process using nitrogen or helium as a propellant gas, little oxidation was observed. Although most of the cross-sections of the coating layers prepared by conventional mechanical polishing looked dense, coating cross sections prepared by an ion-milling method revealed the actual microstructures containing small pores and unbounded interfaces between deposited particles. Even when scanning electron microscopy or x-ray diffraction method did not detect oxides in the coating layers by WS using high nitrogen flow rate or CS using helium, the inert gas fusion method revealed minor increase of oxygen content below 0.3 wt%.
The Synthesis of Titanium Dioxide Powders for Cold Spray
Authors: Tjitra Salim N. , Yamada M. , Nakano H. , Isago H. , Shima K. , Fukumoto M. 
Published: November 2022

Abstract
Titanium dioxide (TiO2) is a unique material that can be used as an excellent photocatalyst, hence it will be very useful to solve the current world pollution problem. For photocatalytic application, the cold spray process, which uses supersonic high velocity technique at moderate temperature is considered to be a suitable technique as it will inhibit the phase transformation of TiO2. It is known that obtaining a thick coating of TiO2 is difficult as it is a hard ceramic material. However, we have successfully synthesised TiO2 powders that can be cold sprayed. Our synthesis technique is a simple hydrolysis method of titanyl sulphate (TiOSO4) in distilled water. It was discovered that the cold sprayability of TiO2 powders is depended on the powder morphology and using our synthesis method, powder morphology can be easily altered. Addition of (NH4)2SO4 during hydrolysis and post synthesis hydrothermal treatment result in a unique oriented aggregated nanostructure of TiO2. Only TiO2 with this nanostructure can be cold sprayed.
Influence of Gas Conditions in Cold Spraying on WC Cermet Coatings
Authors: Sato K. , Seo D. , Furukawa H. , Kitamura J. , Ogawa K. 
Published: November 2022

Abstract
Cold spraying is well known as an attractive coating process that prevents degradation of materials, such as oxidation, decomposition and undesirable reaction due to overheating. High velocity oxy-fuel (HVOF) spraying has been recognized as the most popular technique in particular to produce tungsten carbide (WC) cermet coatings in industrial fields. However, the degradation of WC cermet occurs using HVOF that is quite different from sintered hard metal, which can be defined as an ideal material. Thus, low temperature processes, such as cold and warm spraying, are actively researched to achieve WC cermet coatings, similar to sintered one. In this study, influence of gas conditions in cold spraying on WC cermet coatings has been investigated, where WC-Co, WC-CrC-Ni and WC-Fe alloy are selected. The study reveals that nitrogen gas is effective to form thick, dense and hard coatings of WC-CrC-Ni and WC-Fe alloy compared to helium gas. This suggests optimal temperature and velocity of powder jet has been formed when using nitrogen gas.
Corrosion and Wear Resistance of Molybdenum Containing Arc Spray Composite Coatings
Authors: Laurila J. , Niemi K. , Vuoristo P. , Vajala J. 
Published: November 2022

Abstract
In twin wire arc spraying process it is possible to use feedstock wires of two different compositions at the same time. As a result of this procedure it can be achieved composite coatings called also as pseudo alloys with modified physical properties. In this study nickel and cobalt based super alloy materials were arc sprayed with pure molybdenum wire to tailor corrosion and wear resistance of the coatings. Coatings for the tests were sprayed using two different twin wire Sulzer Metco arc-spraying units, Smart Arc and OSU 300, operating with suitable spray parameters to produce coatings of good quality. It was already known that these twin wire configurations are producing coatings with differing microstructures. Coating sprayed with the OSU system was clearly finer in structure and one purpose of this study was to measure the effect of the micro structural size on the corrosion and wear properties of the final coatings. Microstructures of the coating materials were studied and analyzed from cross-sectional specimens. Volume fraction of pure molybdenum in the coating matrices was evaluated with simple line method and according to the results volume fraction of pure molybdenum metal is over 50 volume-% in all of these tested composite coatings and higher in materials sprayed with OSU unit. Also the microstructure of the coatings was seen to be finer when OSU was used as was expected. Wear resistance was measured with modified ASTM G65 rubber wheel sand abrasion wear test and corrosion resistance was tested in low pH values and chlorine containing environment according to the ASTM G48 corrosion testing standard. Corrosion testing was carried out at room temperature 22°C and also at higher 50°C temperature. Molybdenum addition is clearly improving the abrasion wear resistance of the tested coating systems. At room temperature also the corrosion resistance is getting better with molybdenum addition but at higher temperature this effect is not so clear.
Turbulence Effects in a DC Plasma Torch
Authors: Bolot R. , Allimant A. , Billières D. , Coddet C. 
Published: November 2022

Abstract
The development of new plasma spray torches reinforced the use of numerical modelling to help in the design steps. Most of the thermal spray material providers are thus now interested in understanding the arc behaviour inside the torch so that CFD studies focussed on this topic become numerous. Our first calculations performed on the ProPlasma HP gun assuming a laminar hypothesis have shown underestimations of the torch voltage and of the thermal losses in the cooling circuit, and a subsequent overestimation of the thermal efficiency of the torch. In the present study, the setup of different turbulence models was performed and a comparison was made between the results obtained using either the laminar assumption or several turbulence models. The calculations indicate that the results obtained using conventional turbulence models such as k-ε or k-ω type models do not significantly differ from those obtained using a laminar assumption, thus only more sophisticated models can be expected to improve the simulations.
Effects of Power and Concentration and Dispersion Phase on Nano-Zirconia Coatings Prepared by Sol Plasma Spraying
Authors: Yang H. , Chen L. 
Published: November 2022

Abstract
ZrOCl2•8H2O and NH4OH were regarded as original materials to prepare zirconia sol by co-precipitation, and nano-zirconia coatings were prepared by sol plasma spraying. The structure of the coatings was analyzed by SEM, XRD, and influence of power and stabilizer, concentration and dispersed phase on the coatings was investigated primarily. The result showed that the sol was non-crystal structure after spontaneously dried, the coatings were mixed of nanostructure of monoclinic and cubic phase after plasma jet heated. Increasing power decreased the content of non-crystal phase, adulterating yttria had good crystal phase stabilization, and the content of monoclinic phase decreased greatly. Coatings were denser when higher concentration and ethanol qua dispersed phase were used. Porosity of coatings decreased prior and increased later along with concentration increasing.
Characteristics of Ceramic Coatings Made by Thin Film Low Pressure Plasma Spraying (LPPS-TF)
Authors: Hospach A. , Mauer G. , Vaßen R. , Stöver D. 
Published: November 2022

Abstract
The thin film low pressure plasma spray process (LPPS-TF) has been developed with the aim of efficient depositing uniform and thin coatings with large area coverage by plasma spraying. At high power input (~150 kW) and very low pressure (~100 Pa) the plasma jet properties change considerably and it is even possible to evaporate the powder feedstock material providing advanced microstructures of the deposits. This relatively new technique bridges the gap between conventional plasma spraying and physical vapor deposition. In addition, the resulting microstructures are unique and can hardly be obtained by other processes. In this paper, microstructures made by LPPS-TF are shown and the columnar layer growth by vapor deposition is demonstrated. In addition to the ceramic materials TiO2, Al2O3 or MgAl2O4, the focus of the research was laid on partially yttria-stabilized zirconia. Variations of the microstructures are shown and discussed concerning potential coating applications.
Comparative Characteristics of Coatings Produced from Sn-Sb-Cu Babbitt by Arc Spraying, Gas Surfacing and Pouring
Authors: Korobov Yu. , Nevezhin S. , Potechin B. , Ilushin V. , Gogolev L. 
Published: November 2022

Abstract
Babbitt surfacing is used in tribological applications because of its low friction coefficient. Thermal spray surfacing and pouring are two widely used production processes for Babbitted parts. This paper presents a comparative analysis of structures and friction properties of Sn-Sb-Cu Babbitt layers produced by these techniques. The sprayed Babbitt coatings were produced by arc spraying of 1.6 and 3 mm diameter wire.
Evaluation of the Elastic and Plastic Contact Wear Performance of Plasma and Flame Sprayed 13 and 45 wt% TiO2 Alumina-Titania Coatings
Authors: Vargas F. , Ageorges H. , Fauchais P. , Lopez M. E. 
Published: November 2022

Abstract
Atmospheric plasma and oxy-acetylene flame were used to spray alumina-titania micrometer sized particles with respectively 13 wt.% and 45 wt.% of TiO2 (AT-13 and AT-45). Plasma spraying was also used to spray nanometer-sized- agglomerated particles (AT-13). The enthalpy of spray guns was varied to achieve coatings with different phases and structural characteristics. The influence of the different structural characteristics and the phases of coatings on their hardness and tribological behavior was then studied. The wear resistance was determined by dry elastic contact between an alumina ball, 6 mm in diameter, and the polished coated discs. The ball was moved at a linear speed of 0.1 m/s under a load of 5 N during 20,000 cycles. Drilling tests between a steel drill bit, 12.5 mm in diameter, and the coating surface were also carried out in order to determine the wear resistance under plastic contact. The wear test results showed that AT-13 coatings were more resistant than the AT-45 ones, which was due to the presence of α and γ alumina, phases presenting a high mechanical resistance. On the contrary the resistance of AT-45 coatings, consisting of Al2TiO5 and Al6Ti2O13 brittle phases of low hardness, was poorer. Under elastic contact the reduction of the wear resistance of coatings elaborated by flame spraying was not obvious, but under plastic contact the plasma sprayed coatings were more resistant than those deposited by oxy-acetylene flame.
Microstructure and Wear Resistance of Arc-Sprayed NiCrBSi Coatings after Remelting
Authors: Tillmann W. , Luo W. 
Published: November 2022

Abstract
The anti-wear coatings in this study are developed for the use in forming tools, which need a good resistance against different wear mechanisms such as surface fatigue, adhesion and abrasion. NiCrBSi is suitable for this purpose because of its high resistance against different types of wear at ambient and high temperatures. Due to the low thermal and kinetic energy during the spraying process, the arc-sprayed NiCrBSi coating shows a high interlaminar boundary porosity as well as numerous interface cracks between the coating and the substrate, which can reduce the wear resistance and the adhesion to the substrate. In this work, arc-sprayed NiCrBSi coating were remelted by a treatment with an oxyacetylene flame, induction heating, furnace and laser. The treatment parameters were investigated and optimized. The modified microstructure was characterized using an optical microscope and a scanning electron microscope as wells as an EDS analysis. The hardness of the coatings was evaluated before and after remelting. To examine various wear mechanisms, pin-on-disc tests were conducted with different wear counterpart. The wear and coefficients of the as-sprayed and remelted coating were determined. In order to show the change of the wear resistance as well as the wear mechanisms, wear tracks were characterized with a scanning electron microscope.
Properties of HVOF Sprayed WC-Co Coatings after ESD Process
Authors: Żórawski W. , Radek N. 
Published: November 2022

Abstract
HVOF sprayed coatings are widely used to improve the service life of machines components. Influence of spraying parameters and different kinds of materials on coatings properties have been investigated in many works. Our investigations concern properties of HVOF sprayed two tungsten carbide coatings after applying electrospark deposition process (ESD). After finishing microstructure of sprayed coatings were changed by applying tungsten carbide electrode. Changes of microstructure and properties of the sprayed and post ESD process coatings were analysed with a scanning microscope JOEL JSM-5400. The element distribution was analysed with a microprobe ISIS 300 Oxford Instruments whereas phase composition was analysed by diffractometer D8 Advance (BRUKER). The roughness of coatings was measured with Talysurf-4, whereas Matuzawa MMT-X3A was used to study changes of their hardness. Ball on disc tester and dry abrasive rubber wheel tester were applied to estimate coefficient of friction and wear resistance of sprayed coatings before and after EDM process.
KAJIAN ETNOFISIKA PADA TARI SOYA-SOYA SEBAGAI SUMBER AJAR FISIKA
Authors: Astuti Irnin Agustina Dwi , Sumarni Ria Asep , Setiadi Irawan , Zahra Rachma Azkia 
Published: November 2022

ABSTRAKIndonesia yang memiliki wilayah sangat luas dan memiliki banyak pulau diiringi dengan keanekaragamannya maka Indonesia dikaruniai banyak kearifan lokal. Pelajaran fisika yang rumit untuk dipahami oleh siswa, karena fisika merupakan salah satu mata pelajaran yang dibutuhkan pemahaman konsep antara teori dan penerapan pada kehidupan sehari-hari. Penyajian guru dalam memberikan sebuah materi fisika dan mampu menciptakan suasana kegiatan belajar mengajar interaktif mampu memberikan kesan baik terhadap peserta didik dalam belajar fisika. Tarian daerah sangat kental dengan kearifan lokal daerah tersebut, salah satunya tarian khas Kota Ternate yaitu tari Soya-soya. Maka perlu dikaitkan dengan kegiatan belajar mengajar agar mencegah hilangnya pengetahuan peserta didik tentang kearifan lokal dan mampu mengimplementasikan materi fisika dalam kehidupan sehari-hari maka perlu adanya pengembangan metode pembelajaran, salah satunya dengan menggunakan pendekatan etnofisika. Metode penelitian berupa literature review. Teknik pengumpulan data berupa kajian literatur. Berdasarkan hasil dan pembahasan di atas dapat disimpulkan bahwa setiap gerakan yang dilakukan oleh sang penari Soya-Soya dapat dikaji secara fisika dengan berbagai konsep fisika yang dapat digunakan sebagai bahan ajar fisika di sekolah yang mampu mengasah peserta didik menjadi kreatif dan mampu mengimplementasikan materi dalam kehidupan sehari-hari. Kata kunci: etnofisika; sumber ajar fisika; kearifan local; tari soya-soya. ABSTRACTIndonesia, which has a very large area and has many islands accompanied by its diversity, Indonesia is blessed with a lot of local wisdom. Physics lessons are complicated for students to understand, because physics is one of the subjects that requires understanding the concept between theory and application to everyday life. The presentation of teachers in providing physics material and being able to create an atmosphere of interactive teaching and learning activities is able to give a good impression on students in learning physics. Regional dances are very thick with the local wisdom of the area. One of them is the typical dance of Ternate City, namely the Soya-soya dance. So it needs to be related to teaching and learning activities in order to prevent the loss of knowledge of students about local wisdom and be able to implement physics material in daily life, it is necessary to develop learning methods, one of which is by using an ethnophysical approach. Data collection techniques in the form of literature studies and interviews. Based on the results and discussion above, it can be concluded that every movement performed by the Dancer Soya-Soya can be studied in physics with various physics concepts that can be used as physics teaching materials in schools that are able to hone students to be creative and able to implement the material in daily life. Keywords: ethnophysics; physics teaching resources; local wisdom; soya-soya dance.
ANALISIS SUSEPTIBILITAS MAGNETIK TANAH TPA ANTANG MAKASSAR BERDASARKAN KEDALAMAN
Authors: Mulyana Mulyana , Tiwow Vistarani Arini , Sulistiawaty Sulistiawaty 
Published: November 2022

ABSTRAKAnalisis suseptibilitas magnetik pada tanah di TPA Antang Makassar berdasarkan kedalaman telah dilakukan. Studi ini bertujuan untuk menganalisis jenis mineral magnetik, domain magnetik, dan sumber mineral magnetik. Suseptibilitas magnetik diukur menggunakan alat Bartington MS2 Magnetic Susceptibility Meter dengan sensor MS2B yang bekerja pada dua frekuensi. Pengukuran suseptibilitas magnetik dilakukan dengan mengambil sampel pada lima titik dengan variasi kedalaman hingga 0-80 cm dari permukaan tanah. Hasil pengukuran menunjukkan bahwa nilai suseptibilitas magnetik di TPA Antang bervariasi 2,097 m3/kg hingga 33,523 m3/kg dan suseptibilitas magnetik bergantung frekuensi pada rentangan 2,51% hingga 6,51%. Sampel tanah diindikasikan mengandung mineral magnetik yang bersifat antiferomagnetik dan paramagnetik. Domain magnetik pada sampel tanah adalah superparamagnetik (SP) dan stable single domain (SSD). Sumber mineral magnetik dominan berasal dari aktivitas manusia (antropogenik). Kata kunci: TPA; tanah; suseptibilitas magnetik; mineral magnetik; antropogenik. ABSTRACTMagnetic susceptibility analysis of soil at TPA Antang Makassar based on depth has been carried out. This study aims to analyze the types of magnetic minerals, magnetic domains, and sources of magnetic minerals. Magnetic susceptibility was measured using a Bartington MS2 Magnetic Susceptibility Meter with an MS2B sensor that works on two frequencies. Magnetic susceptibility measurements were carried out by taking samples at five points with depth variations up to 0-80 cm from the ground surface. Measurement results show that the magnetic susceptibility values in Antang landfill varied from 2.097 m3/kg to 33.523 m3/kg and the magnetic susceptibility was frequency dependent in the range of 2.51% to 6.51%. Soil samples are indicated to contain magnetic minerals that are antiferromagnetic and paramagnetic. The magnetic domains in the soil samples are superparamagnetic (SP) and stable single domain (SSD). The dominant source of magnetic minerals comes from human activities (anthropogenic). Keywords: landfill; soil; magnetic susceptibility; magnetic mineral; anthropogenic.
AKTIVITAS SISWA DALAM KEGIATAN ASESMEN PADA PEMBELAJARAN DARING DAN HASIL BELAJAR FISIKA DI SMA
Authors: Pakaya Elvira Ariyanto , Umar Masri Kudrat , Supartin Supartin , Arbie Asri , Setiawan Dewa Gede Eka , Payu Citron S. 
Published: November 2022

ABSTRAKPenelitian ini bertujuan untuk mengetahui dan melihat aktivitas siswa saat kegiatan asesmen dan hasil belajar siswa pada pembelajaran daring pada materi gejala pemanasan global di kelas XI IPA SMA Negeri 1 Kabila, SMA Negeri 1 Tapa, dan SMA Negeri 1 Suwawa. Metode penelitian yang digunakan adalah deskriptif kuantitatif. Subjek penelitian sebanyak 314 siswa kelas XI IPA. Teknik pengumpulan data menggunakan angket dan tes hasil belajar. Teknik analisis data menggunakan analisis secara deskriptif dan analisis kuantitatif. Hasil penelitian ini menunjukan bahwa aktivitas siswa dalam kegiatan asesmen pada pembelajaran daring materi gejala pemanasan global di kelas XI IPA, berdasarkan indikator persiapan dan pelaksanaan dapat dilihat mendapapatkan nilai presentase sebesar 71.06% dengan kriteria cukup baik dan indikator pelaksanaan diperoleh presentase sebesar 67.42% dengan kriteria cukup baik. Hal ini menunjukan bahwa rata-rata peserta didik di 3 sekolah setuju dengan pentingnya kesiapan diri sebelum dan saat kegiatan asesmen dilakukan. Hasil belajar siswa di ketiga sekolah rata-rata berada diatas nilai KKM (75). Untuk nilai rata-rata hasil belajar di SMA Negeri 1 Kabila 77.30, SMA Negeri 1 Tapa 79, dan SMA Negeri 1 Suwawa 76.08. Kata kunci: aktivitas asesmen; pembelajaran daring; hasil belajar. ABSTRACTThis study aims to find out and see the student activities when assessment activities and student learning outcomes in online learning on global warming symptom material in class XI IPA SMA Negeri 1 Kabila, SMA Negeri 1 Tapa, and SMA Negeri 1 Suwawa. The research method used is descriptive quantitative. The research subjects were 314 students of class XI science. Data collection techniques using questionnaires and learning outcomes tests. The data analysis technique used descriptive analysis and quantitative analysis. The results of this study indicate that the assessment activity in online learning material on global warming symptoms in class XI IPA, based on the preparation and implementation indicators, can be seen to get a percentage value of 71.06% with good enough criteria and implementation indicators get a percentage of 67.42% with good enough criteria. This shows that the average student in 3 schools agrees with the importance of self- preparation before and during assessment activities. The average student learning outcomes in the three schools are above the KKM score (75). For the average value of learning outcomes at SMA Negeri 1 Kabila 77.30, SMA Negeri 1 Tapa 79, and SMA Negeri 1 Suwawa 76.08. Keywords: assessment activity; online learning; learning outcomes.