Cemented carbide and coated cemented carbide for cutting tool

摘要

PCT No. PCT/JP94/00596 Sec. 371 Date Mar. 13, 1995 Sec. 102(e) Date Mar. 13, 1995 PCT Filed Apr. 8, 1994 PCT Pub. No. WO95/05497 PCT Pub. Date Feb. 23, 1995A coated cemented carbide comprising: a substrate comprising a WC-based cemented carbide containing 4 to 10 wt. % of Co as a binder phase; based on a ratio in a mirror-polished texture of a cross section of the cemented carbide, 70% or more of WC crystals as a hard phase being classified into either of a group of fine particles A having a particle size of from 0.1 to 1 mu m and a group of coarse particles B having a particle size of from 3 to 10 mu m, the area ratio SA/SB of the fine particles A to the coarse particles B being in a range of from 0.22 to 0.45; and a coating layer disposed on a surface of the cemented carbide and having a total thickness in a range of from 5 to 100 mu m. The coating layer comprises at least one layer comprising at least one selected from the group consisting of: carbides, nitrides, carbonitrides, oxycarbides, and boronitrides of Ti, Zr, and/or Hf; and at least one layer comprising at least one selected from the group consisting of: Al2O3 and oxides of Ti, Zr, or Hf.