| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a covered cutting tool insert and a texture hardenedα-Al<SB>2</SB>O<SB>3</SB>layer to be used in metal machining. <P>SOLUTION: This alumina layer featured in the improved toughness is bonded to a substrate for covering the whole functional portions. A coat is provided with one or more types of heatproof layers including at least one layer which is the texture hardenedα-Al<SB>2</SB>O<SB>3</SB>having a thickness between 2μm and 20μm composed of columnar grains having a length/breadth ratio between 2 and 12. Theα-Al<SB>2</SB>O<SB>3</SB>shows a strong (0006) diffraction peak. The improved wear resistance and toughness are obtained when the texture coefficient (TC) on a (0006) reflection is greater than 1.331nh+2, where h is the thickness of theα-Al<SB>2</SB>O<SB>3</SB>layer, and the surface of theα-Al<SB>2</SB>O<SB>3</SB>layer is wet-blasted up to an Ra value of 1μm or less. The alumina layer with a strong (0001) texture is applied to on a blender phase enrichment hard metal substrate. The combination contributes to enhancement of wear resistance and toughness. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
