Wear of TiC-coated carbide tools in dry turning

Abstract This paper examines the flank and crater wear characteristics of titanium carbide (TiC)-coated cemented carbide tool inserts during dry turning of steel workpieces. A brief review of tool wear mechanisms is presented together with new evidence showing that wear of the TiC layer on both flank and rake faces is dominated by discrete plastic deformation, which causes the coating to be worn through to the underlying carbide substrate when machining at high cutting speeds and feed rates. Wear also occurs as a result of abrasion, as well as cracking and attrition, with the latter leading to the wearing through of the coating on the rake face under low speed conditions. When moderate speeds and feeds are used, the coating remains intact throughout the duration of testing. Wear mechanism maps linking the observed wear mechanisms to machining conditions are presented for the first time. These maps demonstrate clearly that transitions from one dominant wear mechanism to another may be related to variations in measured tool wear rates. Comparisons of the present wear maps with similar maps for uncoated carbide tools show that TiC coatings dramatically expand the range of machining conditions under which acceptable rates of tool wear might be experienced. However, the extent of improvement brought about by the coatings depends strongly on the cutting conditions, with the greatest benefits being seen at higher cutting speeds and feed rates.

[1]  J. Sundgren,et al.  A review of the present state of art in hard coatings grown from the vapor phase , 1986 .

[2]  Seh Chun Lim,et al.  Wear maps for some uncoated cutting tools , 1996 .

[3]  A. B. Chattopadhyay,et al.  Wear and performance of coated carbide and ceramic tools , 1982 .

[4]  Edward M. Trent.  Cutting-tool materials , 1968 .

[5]  P. Rohatgi,et al.  A map for wear mechanisms in aluminium alloys , 1991 .

[6]  Kazuo T. Nakamura,et al.  Applications of wear-resistant thick films formed by physical vapor deposition processes , 1977 .

[7]  Ramon Bakerjian,et al.  Tool and Manufacturing Engineers Handbook , 1989 .

[8]  W. Schintlmeister,et al.  Properties, applications and manufacture of wear-resistant hard material coatings for tools , 1983 .

[9]  E. M. Trent.  Metal cutting and the tribology of seizure: II movement of work material over the tool in metal cutting , 1988 .

[10]  B. P. Sarmah,et al.  Some investigations of the wear mechanisms of widalon carbide inserts in machining EN24 (317 M 40) steel , 1988 .

[11]  Cutting tool materials III , 2000 .

[12]  Michael F. Ashby,et al.  Wear-rate transitions and their relationship to wear mechanisms , 1987 .

[13]  H. Opitz,et al.  Some recent research on the wear behaviour of carbide cutting tools , 1962 .

[14]  E. Trent.  Metal cutting and the tribology of seizure: III temperatures in metal cutting , 1988 .

[15]  H. Jonsson.  Turning of plain carbon steels with TiC-coated and uncoated WC-Co tools in the built-up-edge (BUE) speed range , 1975 .

[16]  D. Rickerby,et al.  The wear and erosion resistance of hard PVD coatings , 1987 .

[17]  J. Billingham,et al.  Coated cutting tools—a study of wear mechanisms in high speed machining , 1980 .

[18]  Seh Chun Lim,et al.  Overview no. 55 Wear-Mechanism maps , 1987 .

[19]  E. M. Trent,et al.  Metal cutting and the tribology of seizure: I seizure in metal cutting , 1988 .

[20]  K.H.W. Seah,et al.  Wear maps for uncoated high-speed steel cutting tools , 1993 .

[21]  Mikael Olsson,et al.  Sliding wear testing of coated cutting tool materials , 1991 .