颗粒含量对TiB2(p)/Fe复合材料显微组织和力学性能的影响  

Effects of Particle Content on Microstructure and Mechanical Properties of TiB2(p)/Fe Composites

作　　者：姚鑫 郭远博 吕超 黄兴民[1] Yao Xin;Guo Yuanbo;Lü Chao;Huang Xingmin(School of Materials Science and Engineering,Southwest Jiaotong University)

机构地区：[1]西南交通大学材料科学与工程学院

出　　处：《特种铸造及有色合金》2020年第3期318-323,共6页Special Casting & Nonferrous Alloys

摘　　要：基于室温单轴拉伸、显微硬度、纳米压痕和扫描电镜观察等试验,表征和分析了TiB2颗粒增强铁基复合材料的宏观、微观力学行为。结果表明,随着高模量TiB2颗粒体积分数从15%增至25%,抗拉强度和弹性模量分别从531.0 MPa和215.5GPa提高到659.0MPa和247.0GPa,比刚度从28.8GPa·cm^-3·g^-1逐步增加至34.7GPa·cm^-3·g^-1,伸长率从22.0%降至7.9%;断裂机制由微孔聚集型韧性断裂转变为穿晶解理型脆性断裂,强化机制可能以细晶强化和位错增殖为主。The macroscopic and microscopic mechanical behaviors of TiB2 particle reinforced iron matrix composites were characterized by room temperature uniaxial stretching,microhardness,nanoindentation and scanning electron microscopy.The results reveal that as the volume fraction of high modulus TiB2 particles increased from15%to 25%,the tensile strength and elastic modulus of the composites are increased from 531.0 MPa and 215.5 GPa to 659.0 MPa and 247.0 GPa,respectively,and the specific stiffness is gradually increased from 28.8 GPa·cm^-3·g^-1 to 34.7 GPa·cm^-3·g^-1,and the total elongation is decreased from 22.0%to 7.9%.The fracture mechanism undergoes the transition from ductile microporous aggregation to brittle transgranular cleavage,while the dominant strengthening mechanism might be fine grain strengthening and dislocation proliferation.

关 键 词：TIB2颗粒 铁基复合材料 纳米压痕 断裂机理 

分 类 号：TB331[一般工业技术—材料科学与工程] TG113.25[金属学及工艺—物理冶金]