中文摘要：

针对均质自润滑陶瓷刀具材料不能合理兼顾减摩性能及耐磨性能的难题，运用功能梯度材料的设计思想研制出一种梯度自润滑陶瓷刀具材料。这种新型自润滑刀具材料的特征是固体润滑剂由其表层向内层梯度减少，并且材料表层存在残余压应力。提出多元梯度材料的组成分布模型，按该模型得出的组分梯度设计结果，采用粉末叠层铺填与真空热压烧结工艺制备Al2O3／TiC／CaF2梯度自润滑陶瓷刀具材料。该梯度自润滑陶瓷刀具材料的显微结构呈现出与组成分布一致的梯度变化，表层形成了残余压应力，其抗弯强度、硬度和断裂韧度分别比相应的均质材料提高了21％、16％和5．9％。材料强度的提高主要是由于CaF2由表层到中间层梯度减少，硬度和断裂韧度的提高归因于材料表层的残余压应力。以Al2O3／TiC／CaF2梯度自润滑陶瓷刀具和相应的均质自润滑陶瓷刀具对45钢进行干切削试验，结果表明，梯度刀具的耐磨性能优于均质刀具。

英文摘要：

Aiming at the problem that homogeneous self-lubricating ceramic cutting tool materials are not available to possess rational combination of antifriction and antiwear properties, a graded self-lubricating ceramic cutting tool material is developed by applying the design concept of functionally graded materials. The new type of self-lubricating cutting tool material is characterized by the solid lubricant＇s decreasing distribution from the outer layers to the inner layers and the residual compressive stresses existing in the surface layers. A multicomponent distribution model is proposed. According to the model, Al2O3/TiC/CaF2 graded self-lubricating ceramic cutting tool material is compositionally designed and then is prepared by using the process of laminated padding and hot press in vacuum. The microstructure of the graded self-lubricating ceramic cutting tool material changes in accordance with the compositional distribution. Residual compressive stresses are formed in the surface layers. Compared with the corresponding homogeneous material, flexural strength, hardness and fracture toughness of the Al2O3/TiC/CaF2 graded self-lubricating ceramic cutting tool material are increased by 21%, 16% and 5.9%, respectively. The flexural strength is increased mainly because CaF2 in the material decreases from the surface layers to the middle layer. The improvement in the hardness and fracture toughness is attributed to the residual compressive stresses in the surface layers. Dry cutting tests are carried out on 45 steel with Al2O3/TiC/CaF2 graded self-lubricating ceramic cutting tool and the corresponding homogeneous cutting tool. Results show that wear resistance of the graded cutting tool is superior to that of the homogeneous cutting tool.