添加固体润滑剂的自润滑陶瓷刀具材料及其减摩机理研究

采用热压工艺制备Al2O3/TiC/CaF2(ATF)自润滑陶瓷刀具材料,考察其室温下的机械性能,并通过切削性能试验分析其切削减摩机理。结果表明:添加固体润滑剂对陶瓷材料的机械性能有一定影响,其中CaF2含量为10%的Al2O3/TiC/CaF2陶瓷材料的力学性能最好,强度和硬度最高,分别达到了589MPa和HV15·4GPa,可以用作刀具材料;ATF自润滑陶瓷刀具在切削过程中,减摩性能优于LT55陶瓷刀具,能够在前刀面形成一层较完整的固体润滑膜,膜的存在使得ATF自润滑刀具材料具有一定的减摩能力,而后刀面具有磨粒磨损的特征,由于磨粒的刻划作用而没有形成较完整的润滑膜。

Self-lubricating Ceramic Tool with Addition of Solid Lubricant and Its Self-lubricating Mechanism

A Al2O3/TiC self-lubricating ceramic tool with the addition of CaF2 was produced by hot pressing. Mechanical properties were analyzed and dry cutting tests were carried out with respect to 45# steel and Al2O3/TiC/CaF2 (ATF) self-lubricating ceramic cutting tools. The morphologies of rake face and rear face of the tool cutting steel in air were observed on a scanning electron microscope. It was found that the composite with 10% CaF2 content, which can be used as cutting tool, showed higher flexural strength, fracture toughness, and hardness compared with that of the composites with 5% and 15% CaF2 content owing its porosity absent and finer microstructure. The friction coefficient of ATF tool was lower than that of LT55, accounting for a lubricating layer generated on the rake surface of ATF tool and the film having lubricating function,while there was no a lubricating film on the rear face of the ATF tool.