摘要
采用先进粉末冶金技术(放电等离子烧结+热挤压)制备了三种体积分数(3vol%、5vol%、7vol%)的微/纳B_(4)C增强6061Al复合材料,对不同制备阶段复合材料的微观组织(SEM、TEM、EBSD)进行观察分析,对复合材料的纳米压痕行为及拉伸性能进行测试。结果表明:烧结后B_(4)C颗粒在基体中呈"网状"分布;挤压变形后B_(4)C颗粒在基体实现弥散均匀分布。挤压变形后,纳米B_(4)C在晶内及晶界均有分布,纳米B_(4)C对位错的钉扎作用使得基体积累大量位错,提供驱动力并越过动态回复,使内部再结晶比例高达74%。当B_(4)C体积分数为3vol%时,挤压态B_(4)C/6061Al复合材料的抗拉强度、屈服强度及延伸率为219 MPa、88 MPa和22.5%,断裂形貌中呈现大量韧窝。
Micro/nano B_(4)C particle reinforced 6061 Al composites with three volume fractions(3 vol%, 5 vol%,7 vol%) were prepared by advanced powder metallurgy technology(spark plasma sintering +hot extrusion). The microstructure evolution at different stages was observed by SEM, TEM and EBSD. The nano-indentation behavior,tensile properties and friction and wear properties were also tested. Results show that B_(4)C particles distribute in a network structure after sintering, and the B_(4)C particles are dispersed uniformly after extrusion. The nano-B_(4)C particles are distributed in the grains and grain boundaries. The pinning effect of nano-B_(4)C on the dislocation accumulates a large number of dislocations in the matrix, which provides driving force and overrides the dynamic recovery. Finally, the recrystallization ratio reaches 74%. When the volume fraction of B_(4)C is 3 vol%, the tensile strength,yield strength and elongation of as-extruded B_(4)C/6061 Al composites are 219 MPa, 88 MPa and 22.5%, and a large number of dimples appear in the fracture morphology.
作者
刘瑞峰
王文先
赵威
LIU Ruifeng;WANG Wenxian;ZHAO Wei(College of Aeronautics and Astronautics,Taiyuan University of Technology,Taiyuan 030024,China;College of Materials Science and Engineering,Taiyuan University of Technology,Taiyuan 030024,China)
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
2021年第10期3394-3401,共8页
Acta Materiae Compositae Sinica
基金
国家自然科学基金(51775366)。
