HARD-ALLOY ARTICLES PRODUCTION METHOD OF LUMPY WASTE OF COBALT-CONTAINING HARD ALLOYS Russian patent published in 2008 - IPC B22F3/12 B22F9/04 C22C29/08 

FIELD: powder metallurgy, namely production of hard alloys, possibly manufacture of wear resistant hard-alloy articles of waste material of hard alloys.

SUBSTANCE: method comprises steps of preparing charge by breaking lumpy waste material containing 4, 6, 8 or 10 mass % of cobalt; screening it for separating fraction with size 60- 120 micrometers and subjecting to electromagnetic concentration; adding to concentrated powder 20 - 30 mass% of hard-alloy charge with the same content of cobalt as waste material or adding 20 -30 mass % of hard-alloy charge having cobalt content exceeding by 2 mass% or 4 mass% cobalt content of waste material while adding the same content of cobalt to concentrated powder. Fine grinding is realized in vibration grinding mill till mean size of particles 3 - 4 micrometers. The blanks are pressed, dried and sintered in vacuum at temperature 1390 - 1420°C.

EFFECT: high hardness, improved bending strength, decreased cost price of produced hard alloy article.

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