Forces in the static and dynamic pressing of metal powders and chips

The equipment for the production of wide range of metal powders purposed for powder metallurgy is described. The possibility for producing of powders by the plasma centrifugal spraying is considered taking into account the gas dynamic pressure. The calculated data on the powder size for different materials are given.

Download Full-text

Preparation and Study of Highly Reactive Metal Powders

10.21236/ada150026 ◽

1984 ◽

Author(s):

Reuben D. Rieke

Keyword(s):

Metal Powders ◽

Reactive Metal

Download Full-text

Diffusion Saturation of U8A Steel in a Mixture of Metal Powders with the Chloride Ammonia

Journal of Nano- and Electronic Physics ◽

10.21272/jnep.11(3).03022 ◽

2019 ◽

Vol 11 (3) ◽

pp. 03022-1-03022-7

Author(s):

V. G. Hignjak ◽

◽

T. V. Loskutova ◽

G. Y. Calashnicov ◽

I. S. Pohrebova ◽

...

Keyword(s):

Diffusion Saturation ◽

Metal Powders

Download Full-text

Investigation of pre-sprayed powders for electric contact welding

Tekhnicheskiy servis mashin ◽

10.22314/2618-8287-2020-58-1-143-149 ◽

2020 ◽

pp. 143-149

Author(s):

Dinar R. Masalimov ◽

Roman R. Galiullin ◽

Rinat N. Sayfullin ◽

Azamat F. Fayurshin ◽

Linar F. Islamov

Keyword(s):

Adhesion Strength ◽

Electrical Contact ◽

Research Purpose ◽

Flame Spraying ◽

Powder Materials ◽

Electric Contact ◽

Metal Powders ◽

Unstable Flow ◽

Gas Flame ◽

Contact Welding

There are a number of difficulties in the electrical contact welding of powder materials: shedding of powder from the surface of a cylindrical part, impossibility of hardening the layer during welding due to flushing of the powders with coolant and unstable flow of powder into the welding zone. One solution is pre-spraying the powder in some way. (Research purpose). The research purpose is investigating the possibility of electric contact welding of metal powders preliminarily sprayed by a gas-flame method, namely, adhesion strength and losses during preliminary gas-flame spraying of powders. (Materials and methods) Powders of grades PG-NA-01, PrKhIIG4SR, PRZh3.200.28 were sprayed onto flat samples of St3 steel, polished to a roughness of Ra 1.25. The strength of powder adhesion to the base was studied by the cut method. (Results and discussion) The percentage loss of the powder as a whole is 3-23 percent for all the distances studied. The greatest powder losses appear at a distance of more than 180 millimeter from the tip of the burner for powders of grades PG-NA-01 and PrKhIIG4SR. The smallest powder losses were observed for PrZh3.200.28 powder, which totaled 3-7 percent. The maximum adhesion strength of the sprayed powders to the surface was 22.1 megapascals' when spraying the PG-NA-01 powder. The adhesion strength of powders of the grades PrKhIIG4SR and PrZh3.200.28 is small and amounts to 0.2-3 megapascals'. (Conclusions) The use of preliminary flame spraying of powders for their further electric contact welding is possible using PG-NA-01 grade powder, while the best adhesion to the base (that is more than 20 megapascals') is achieved with a spraying distance of 120-140 millimeter. The smallest powder losses during flame spraying are achieved at a spraying distance of 100-160 centimeters', at which the powder loss for the studied grades was 4-12 percent.

Download Full-text