关键词: 反应烧结;碳化硼;炭黑;硼化钛;二氧化钛

Abstract: Boron carbide is a kind of potential structural ceramic with wide application.Boron carbide has excellent properties such as low density, high strength, high hardness, abrasion resistance and corrosion resistance, but it has the characteristics in poor toughness and high sintering temperature that limit its broader application.TiB2-reinforced B4C ceramics were prepared by in-situ synthesis and Si-infiltration reaction sintering.The mechanical properties and microstructures of composite ceramics with TiO2 particles were investigated.The results show that the distribution of in-situ particles is more uniform and the grain size is more fine;and the distribution of TiB2 is on the boundary of B4C.It plays a positive role in the toughening and strengthening of B4C ceramic materials.When the amount of TiO2 addition reaches 8wt;, the maximum flexural strength is 269 MPa and the maximum fracture toughness is 7.73 MPa·m1/2, which is 2.46 times of B4C ceramic material with TiO2 content of 0wt;.

Key words: Boron carbide is a kind of potential structural ceramic with wide application.Boron carbide has excellent properties such as low density, high strength, high hardness, abrasion resistance and corrosion resistance, but it has the characteristics in poor toughness and high sintering temperature that limit its broader application.TiB2-reinforced B4C ceramics were prepared by in-situ synthesis and Si-infiltration reaction sintering.The mechanical properties and microstructures of composite ceramics with TiO2 particles were investigated.The results show that the distribution of in-situ particles is more uniform and the grain size is more fine;and the distribution of TiB2 is on the boundary of B4C.It plays a positive role in the toughening and strengthening of B4C ceramic materials.When the amount of TiO2 addition reaches 8wt;, the maximum flexural strength is 269 MPa and the maximum fracture toughness is 7.73 MPa·m1/2, which is 2.46 times of B4C ceramic material with TiO2 content of 0wt;.