Is superior in abrasion resistance and tenacity the cemented carbide component

摘要

PURPOSE:To improve the wear resistance and toughness of an alloy member by specifying the ratio of the total content of WC and NaCl-type crystalline structural compounds to the content of NaCl type crystalline structural compounds contained in a bonding phase forming component deficient hard layer and a bonding phase forming component enriched soft layer formed on the surface at the inside of a sintered hard alloy. CONSTITUTION:A bonding phase forming component deficient hard layer is formed on the surface at the inside of an ordinary sintered hard alloy, and, directly below the above, a bonding phase forming component enriched soft layer excellent in toughness is formed in contact with the inside of the sintered hard alloy. At the time of denoting the ratio of the total content of WC and NaCl type crystalline structural compounds to the content of NaCl type crystalline structural compounds in the inner part of the sintered hard alloy as A, the value of (NaCl type crystalline structural compounds)/(WC+NaCl type crystalline structural compounds) in the above both layers is regulated to the almost same one in the range of 0.8 to 1.2 A. A cutting tool manufactured by using this sintered hard alloy can be used over a long period even for heavy cutting.