Influence of Preliminary Heat Treatment and Ball Milling of Aluminum Powder on Cold Spray Process

2021 ◽  
Vol 313 ◽  
pp. 127-135
Author(s):  
S.V. Klinkov ◽  
V.F. Kosarev ◽  
A.E. Chesnokov ◽  
A.V. Smirnov ◽  
V.S. Shikalov
Keyword(s):  
Heat Treatment ◽  
Ball Milling ◽  
Aluminum Powder ◽  
Cold Spraying ◽  
Preliminary Heat Treatment ◽  
Aluminum Powders ◽  
Aluminum Coatings ◽  
Spray Process ◽  
Spraying Process ◽  
Milled Powders

This paper presents the results of a study of the effect of preliminary heat treatment and ball milling of aluminum powder on the cold spraying process and the properties of the obtained coatings (porosity and microhardness). The ball milling of aluminum powder leads to an increase in specific surface area, a decrease in apparent density and a decrease in the value of the crystallite size, which indicates a decrease in grain size. It is shown that coatings deposited from ball milled powders have slightly higher coatings hardness averagely. The profilometry of aluminum coatings obtained under the same conditions from the initial and processed powders did not reveal significant changes in the form of coatings and their typical dimensions (width, thickness), which indicates the absence of significant changes in the deposition coefficient of the initial and processed aluminum powders. Ball milled powders on average correspond to slightly higher hardnesses of coatings.

Influence of preliminary heat treatment and ball milling of copper powder on cold spray process

2020 ◽  
Vol 25 ◽  
pp. 360-362
Author(s):  
S.V. Klinkov ◽  
V.F. Kosarev ◽  
V.S. Shikalov ◽  
T.M. Vidyuk ◽  
A.E. Chesnokov ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Ball Milling ◽  
Cold Spray ◽  
Copper Powder ◽  
Preliminary Heat Treatment ◽  
Cold Spray Process ◽  
Spray Process

Structures and Properties of Laser-Assisted Cold-Sprayed Aluminum Coatings

2016 ◽  
Vol 879 ◽  
pp. 984-989 ◽  
Author(s):  
Heli Koivuluoto ◽  
Andrea Milanti ◽  
Giovanni Bolelli ◽  
Jyrki Latokartano ◽  
Francesco Marra ◽  
...  
Keyword(s):  
Cold Spray ◽  
Cold Spraying ◽  
Cost Effective ◽  
Deposition Efficiency ◽  
Solid Particles ◽  
Aluminum Coatings ◽  
Spray Process ◽  
Structures And Properties ◽  
High Kinetic Energy ◽  
Laser Heated

In the cold spray process, solid particles impact on a surface with high kinetic energy, deform plastically and form a coating. This enables the formation of pure and dense coating structures. Even more, coating performance and deposition efficiency can be improved by assisting the process with a laser. Laser-assisted cold spraying (LACS) has shown its potential to improve coating properties compared with traditional cold spraying. In this study, coating quality improvement was obtained by using a co-axial laser spray (COLA) process which offers a new, cost-effective laser-assisted cold spray technique, for high-quality deposition and repair. In the COLA process, the sprayed surface is laser heated while particles hit the surface. This assists the better bonding between particles and substrate and leads to the formation of tight coating structures. This study focuses on the evaluation of the microstructural characteristics and mechanical properties (e.g., hardness and bond strength) of LACS metallic coatings.

Effect of Boron and Carbon Addition on the Phase Transformations during High-Energy Ball Milling and Subsequent Sintering of Si3N4+B and Si3N4+C Powder Mixtures

2016 ◽  
Vol 869 ◽  
pp. 58-63
Author(s):  
Luiz Otávio Vicentin Maruya ◽  
Bruna Rage Baldone Lara ◽  
Belmira Benedita de Lima ◽  
Vanessa Motta Chad ◽  
Gilberto Carvalho Coelho ◽  
...  
Keyword(s):  
Phase Transformations ◽  
Ball Milling ◽  
Weight Ratio ◽  
High Energy ◽  
Ceramic Composites ◽  
Nitrogen Atmosphere ◽  
Carbon Addition ◽  
Powder Mixtures ◽  
X Ray ◽  
Milled Powders

This study reports on effect of boron and carbon addition on the phase transformations during ball milling and subsequent sintering of Si3N4+B and Si3N4+C powder mixtures. Ball milling at room temperature was conducted using stainless steel vials (225 mL) and balls (19mm diameter), 300 rpm and a bal-to-powder weight ratio of 10:1. The as-milled powders were uniaxially compacted in order to obtain cylinder samples with 10 mm diameter, which were subsequently sintered under nitrogen atmosphere at 1500°C for 1h. Characterization of the as-milled powders and sintered samples was performed by X-ray diffraction, scanning electron microscopy, and energy dispersive spectrometry. Only peaks of Si3N4 were identified in X-ray diffractograms of as-milled Si3N4+B and Si3N4+C powders, suggesting that metastable structures were found during milling. After sintering at 1500°C for 1h, the Si3N4+BN and Si3N4+SiC ceramic composites were formed from the mechanically alloyed Si3N4+B and Si3N4+C powders.

Intermetallic Effects on the Ductility of Sintered Aluminium

2008 ◽  
Vol 587-588 ◽  
pp. 380-384
Author(s):  
Jesus Cintas ◽  
José A. Rodríguez ◽  
Francicso Gomez Cuevas ◽  
José M. Gallardo
Keyword(s):  
Heat Treatment ◽  
Particle Size ◽  
Intermetallic Particle ◽  
Quantitative Metallography ◽  
Mechanically Alloyed ◽  
Aluminium Powder ◽  
Attrition Milling ◽  
Different Temperatures ◽  
Alloyed Aluminium ◽  
Milled Powders

Mechanically alloyed aluminium powder was prepared by attrition-milling for 10 hours in the presence of a wax. Milled powders were annealed in vacuum at different temperatures (500, 575, 600, 625 and 650°C). Compacts were consolidated starting from unannealed and from 600°Cannealed powders. Studies by SEM microfractography and quantitative metallography, to investigate the influence of Fe-Al intermetallics on compacts fracture, have been carried out. It is concluded that fracture takes place at regions where the area occupied by the intermetallics is high and intermetallics particles are big. Intermetallic particle size can be controlled by an appropriated heat treatment.

Substantiation into Parameters of Carbon Fuel Production Technology from Brown Coal

2021 ◽  
Vol 1045 ◽  
pp. 90-101
Author(s):  
Oleksandr Shustov ◽  
Artem Pavlychenko ◽  
Andrii Bondarenko ◽  
Oleksandr Bielov ◽  
Olena Borysovska ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Brown Coal ◽  
Vacuum Drying ◽  
Preliminary Heat Treatment ◽  
Fuel Production ◽  
Thermal Coal ◽  
Heat Treated ◽  
Thermal Influence ◽  
Coking Products ◽  
Qualitative And Quantitative Characteristics

Technological solutions for brown coal processing, thermal influence on it at temperature change, thermo vacuum drying are analysed and qualitative and quantitative characteristics of semi – coking products are studied. The parameters of crushing and thermo vacuum drying of brown coal, heat treatment and cascade separation (electrostatic and magnetic) are substantiated. Studies on the manufacture of a pilot batch of carbon fuel with high quality characteristics are performed. Cascade treatment of heat-treated brown coal on electric and magnetic separators allowed to obtain a concentrate with ash content from 17.72 to 22.8%, volatile yield ≤ 35%, higher heat of combustion from 7256.1 to 7523.6 kcal/kg. It is determined that favourable modes of preliminary heat treatment of brown coal samples are in the temperature range of 200-400°С. The established characteristics of the obtained solid fuel correspond to the gas group of thermal coal. The obtained technological solutions for the processing of brown coal can be the basis for the manufacture of an industrial line, taking into account the thermo vacuum installation for further implementation in enterprises using carbon fuel.

scholarly journals RESEARCH OF THE PROCESS OF EXTRACTION OF BLACK CUMIN OIL WITH PRELIMINARY HEAT TREATMENT

2021 ◽  
pp. 66-69
Keyword(s):  
Heat Treatment ◽  
Treatment Process ◽  
Acid Number ◽  
Oil Yield ◽  
Preliminary Heat Treatment ◽  
Heat Treatment Process ◽  
Drying Process ◽  
Technological Parameters ◽  
Variable Parameters ◽  
Black Cumin

The aim of the study is to increase the yield of oil from black cumin seeds. The results of studies of the influence of technological parameters - temperature and duration of drying of black cumin seeds on indicators of the yield of oil, cake and moisture removal from seeds are presented. The optimal technological parameters of the influence of the preliminary heat treatment process on the indicators of the maximum oil yield, acid number, color, and oil moisture have been established. The variable parameters were the temperature from 80 to 130 °C and the duration of the heat treatment process from 5 to 60 minutes. The possibility of increasing the oil yield by 6,11% has been shown. For this, the drying process must be carried out at a temperature of 100 °C and a process duration of 15 minutes. At the same time, the degree of oil extraction increases from 59,13% to 75,24%, the acid number decreases to 2,98, humidity to 0,12%, and color to 40.

scholarly journals Comparison of structure and magnetic properties of Mn–Zn ferrite mechanochemically synthesized under argon and oxygen atmospheres

2015 ◽  
Vol 93 (10) ◽  
pp. 1168-1173 ◽  
Author(s):  
Mohamad Taghi Masoudi ◽  
Ali Saidi ◽  
Mansor Hashim ◽  
Abdollah Hajalilou
Keyword(s):  
Electron Microscopy ◽  
Crystallite Size ◽  
Ball Milling ◽  
Spinel Phase ◽  
Average Crystallite Size ◽  
Argon Atmosphere ◽  
Diffusion Reaction ◽  
Particle Structure ◽  
Zn Ferrite ◽  
Milled Powders

Nanocrystalline Mn0.5Zn0.5Fe2O4 ferrite was successfully synthesized by ball milling a powder mixture of MnO, ZnO, and Fe2O3 under argon and oxygen atmospheres. The effects of the milling time, milling atmosphere, and annealing temperature on the milled powders were examined. X-ray diffractometry (XRD), scanning electron microscopy, and transmission electron microscopy were used to evaluate the powder particle structure. The XRD results indicated that after 20 h of ball milling the MnO–ZnO–Fe2O3 powder reacted with a solid-state diffusion reaction route producing Mn–Zn ferrite nanoparticles in the milled samples with both atmospheres. However, some Fe3O4 phase alongside Mn–Zn ferrite, both being spinel-phase, was detected for 40 h milled powders in the argon atmosphere. Those milled powders in the argon atmosphere had smaller crystallite size than the other ones. In the final stage of milling (40 h), the average crystallite size and lattice strain were 20 nm and 0.51%, respectively, ans 25 nm and 0.48% for milled samples in the argon and oxygen atmospheres, respectively. Vibrating sample magnetometer results indicate that the saturation magnetization and coercivity were 34 emu/g and 30 Oe, 18 emu/g and 70 Oe, respectively, for the 40 h milled samples in argon and oxygen, which were annealed at 800 °C for 2 h.

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