High Impact Strength of Powder Chromium Sintered in Magnesium Vapors

I.Slys,
  
I.Kossko,
   

I. M. Frantsevich Institute for Problems of Materials Science of the NAS of Ukraine, Krzhizhanovsky str., 3, Kyiv, 03142, Ukraine
Powder Metallurgy - Kiev: Frantsevich Institute for Problems of Materials Science NASU, 2012, #05/06
http://www.materials.kiev.ua/article/1032

Abstract

The impact strength of powder chromium sintered in magnesium vapors is higher by 53 times than that of powder chromium sintered in hydrogen and by five times higher than that of as-cast, deformed low-alloy chromium alloy VKh2K. The high impact strength is due to the formation of a skeleton from plastic interlayers of high-purity chromium. Chromium has high plasticity when purified in Cr–MgO alloys to remove interstitial impurities. The interlayers form on the surface of chromium powder particles resulting from refining in magnesium vapors. According to Auger electron microscopy, data on the nature of fracture, chemical composition, and etching resistance, it is concluded that interlayers of pure chromium are formed. The high impact strength is retained after annealing for one h at 1500 0C.


ACTIVATED SINTERING, CHROMIUM, FRACTURE TOUGHNESS, IMPACT STRENGTH, MAGNESIUM, PLASTICITY, REFINING