Sintering of a nano-crystalline tungsten heavy alloy powder

Autor: Jalil Vahdati Khaki, Hosein Arabi, Ahmad Ghaderi Hamidi
Rok vydání: 2019
Předmět:
Zdroj: International Journal of Refractory Metals and Hard Materials. 80:204-209
ISSN: 0263-4368
DOI: 10.1016/j.ijrmhm.2019.01.016
Popis: A nano-crystalline Tungsten heavy alloy powder was obtained by mechanical alloying of elemental powders in a jar mill with a high ball to powder ratio. The chemical composition of the primary powder was 93 W-4.9Ni-2.1Fe (wt%). The mechanically alloyed powder had 22 nm sized tungsten crystallites distributed in an amorphous nickel base phase. Mechanical alloying reduced particle size of powders and also yielded to more uniform particles size distribution. Sintering behavior and microstructural development of that powder were studied and compared with a conventionally mixed powder. Mechanically stored energy and better distribution of primary elements in Nano-crystalline powder had decreased motivation energy of sintering and that powders showed more densification at relatively lower sintering temperatures. Sintering at low temperatures can depress grain growth during sintering and provide desirable properties. A transient intermetallic phase was formed in the nano-crystalline powder during sintering that has not been seen in conventionally mixed powders.
Databáze: OpenAIRE