Al_2O_3基复合金属陶瓷模具材料的组织结构与力学性能

Microstructure and mechanical properties of Al_2O_3 matrix composite metal ceramic die materials

以纳米Al_2O_3和纳米Ti(C,N)为主要原料,以Mo和Ni粉等为助烧剂,采用N2气氛保护热压工艺制备Al_2O_3基复合金属陶瓷模具材料。采用XRD和SEM分析材料的物相组成及微观结构,并测试材料的力学性能。结果表明,当烧结温度为1 660℃,纳米Al_2O_3质量分数为74.5%,纳米Ti(C,N)粉为20%、Mo+Ni粉为5%时,所制备的Al_2O_3基复合金属陶瓷模具材料性能最佳,其相对密度为98.14%,弯曲强度值为795.98 MPa,硬度值为18.52 GPa,断裂韧性为8.05 MPa·m1/2。第二相的引入和晶界处Mo+Ni的共同作用,可增强晶界强度,促进沿晶裂纹向穿晶裂纹转变,从而提高材料的力学性能。

The alumina matrix composite metal-ceramic die materials were fabricated by hot-pressing sintering technique in N2 atmosphere using nano Al2O3 and Ti(C,N)as the main raw materials,Mo and Ni as sintering additives.The phase composition and microstructure were tested and analyzed by XRD and SEM.The mechanical property was also studied.The results show that when the sintering temperature is 1 660℃,the mass fraction of nano Al2O3 is 74.5%,nano Ti(C,N)is 20%and Mo+Ni is 5%,the prepared alumina matrix composite metal ceramic die material can obtain the optimal properties.And the relative density is 98.14%,flexural strength is 795.98 MPa,hardness is 18.52 GPa and fracture toughness is 8.05 MPa·m^1/2.Introduced second phase and Mo+Ni in the boundary of crystal can increase the crystal boundary strength,accelerate intergranular crack transit to transgranular cracks,then enhance mechanical properties of the samples.