Method of making a cemented carbide body with increased wear resistance
AssigneeSandvik AB
InventorMats Waldenström
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Abstract
The present invention relates to a method of making a cemented carbide body with a bimodal grain size distribution by powder metallurgical methods including wet mixing, without milling, of WC-powders with different grain size distributions with binder metal and pressing agent, drying, pressing and sintering. The grains of the WC-powders are classified in at least two groups, a group of smaller grains and a group of larger grains. According to the method of the present invention, the grains of the group of smaller grains are precoated with a growth inhibitor with or without binder metal.
Claims27
A method of making a cemented carbide body with a bimodal grain size distribution comprising the steps of:
- (i) wet mixing, without milling, WC-powders with a binder metal and a pressing agent, the WC powders comprising smaller grains precoated with a grain growth inhibitor, and larger grains;
- (ii) drying the mixture of step (i);
- (iii) pressing the dried mixture to form a pressed body;
- and
- (iv) sintering the pressed body.
A method of making a cemented carbide body comprising the steps of:
- (i) providing a WC powder, the WC powder comprises a group of fine WC grains and a group of course WC grains;
- (ii) precoating the fine WC grains with a grain growth inhibitor;
- (iii) precoating the course WC grains with a binder metal;
- (iv) wet mixing, without milling, the precoated fine WC grains, the precoated course WC grains, additional binder metal and a pressing agent;
- (v) drying the mixture of step (iv);
- (vi) pressing the dried mixture to form a pressed body;
- and
- (vii) sintering the pressed body.
Dependencies are inferred from the claim text.