Self-lubrication of sintered ceramic tools with CaF2 additions in dry cutting

Abstract An Al 2 O 3 /TiC ceramic cutting tool with the additions of CaF 2 solid lubricant was produced by hot pressing. The fundamental properties of this ceramic cutting tool were examined. Dry machining tests were carried out on hardened steel and cast iron. The tool wear, the cutting forces, and the friction coefficient between the tool–chip interface were measured. It was shown that the friction coefficient at the tool–chip interface in dry cutting of hardened steel and cast iron with Al 2 O 3 /TiC/CaF 2 ceramic tool was reduced compared with that of Al 2 O 3 /TiC tool without CaF 2 solid lubricant. The mechanisms responsible were determined to be the formation of a self-lubricating film on the tool–chip interface, and the composition of this self-lubricating film was found to be mainly CaF 2 solid lubricant, which was released and smeared on the wear track of the tool rake face, and acted as lubricating additive between the tool–chip sliding couple during machining processes. The appearance of this self-lubricating film contributed to the decrease of the friction coefficient. Cutting speed was found to have a profound effect on this self-lubricating behavior.

[1]  Said Jahanmir,et al.  Friction and Wear Characteristics of Silicon Nitride-Graphite and Alumina-Graphite Composites© , 1991 .

[2]  M. Fine,et al.  Tribological Behavior of SiC‐Whisker/Al2O3 Composites against Carburized 8620 Steel in Lubricated Sliding , 1991 .

[3]  Sture Hogmark,et al.  Sliding wear and friction of Si3N4-SiC-based ceramic composites containing hexagonal boron nitride , 1998 .

[4]  Peter J. Blau,et al.  Reciprocating friction and wear behavior of a ceramic-matrix graphite composite for possible use in diesel engine valve guides , 1999 .

[5]  J. Mukerji,et al.  Tribological properties of Al2O3-TiN composites , 1998 .

[6]  P. Sreejith,et al.  Dry machining: Machining of the future , 2000 .

[7]  Jianxin Deng.  WEAR, LUBRICATION AND MATCHING OF CERAMIC CUTTING TOOLS WITH THE WORKPIECE MATERIALS , 2002 .

[8]  F. J. Worzala,et al.  Friction and wear properties of partially stabilized zirconia with solid lubricant , 1993 .

[9]  G. Brandt,et al.  Ceramic Cutting Tools, State of the Art and Development Trends , 1999 .

[10]  P. Becher.  Microstructural design of toughened ceramics , 1991 .

[11]  Hua-ming Wang,et al.  Microstructure and tribological properties of laser clad CaF2/Al2O3 self-lubrication wear-resistant ceramic matrix composite coatings , 2002 .

[12]  A. Evans.  Perspective on the Development of High‐Toughness Ceramics , 1990 .

[13]  Fritz Klocke,et al.  Coated Tools for Metal Cutting – Features and Applications , 1999 .

[14]  M. C. Nichols,et al.  Effect of Thermal History on the Properties of a Willemite Glass‐Ceramic , 1983 .

[15]  R. Cook,et al.  A Modified Indentation Toughness Technique , 1983 .

[16]  Harold E. Sliney,et al.  Solid lubricant materials for high temperatures: A review , 1982 .

[17]  A. Xing,et al.  Friction and wear behavior of Al2O3/TiB2 composite against cemented carbide in various atmospheres at elevated temperature , 1996 .

[18]  D. Jianxin.  Friction and wear behaviour of Al2O3/TiB2/SiCw ceramic composites at temperatures up to 800°C , 2001 .