TiO2颗粒原位合成TiB2对B4C陶瓷材料组织与力学性能的影响

碳化硼是一种应用广泛且极具潜力的结构陶瓷,具有低密度、高强度、高硬度、耐磨损、耐腐蚀等优良性能,但是韧性差、烧结温度高的特性限制了其更为广泛的应用.本文采用原位合成和硅溶渗反应烧结相结合的方式制备TiB2增强B4C陶瓷材料,再分别对所制备的复合陶瓷材料的力学性能和显微组织进行研究,研究结果表明:原位合成的TiB2颗粒分布更加均匀,晶粒更加细小且原位合成的TiB2颗粒主要分布在B4C边界,对B4C陶瓷材料起到增韧补强的作用;当添加量达到8wt;时,弯曲强度出现最大值为269 MPa,断裂韧性最大值为7.73 MPa·m1/2,是TiO2添加量为0wt;的B4C陶瓷材料的2.46倍.

Effect of In-situ Synthesis of TiB2 Particles on Microstructure and Mechanical Properties of B4C Ceramics

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%.