Microstructure and Mechanical Properties of B4C/6061Al Composites Welded Joints
Due to the special thermal neutron capturing ability of the 10B isotope,B4C/Al metal matrix composites (MMCs) have become increasingly used as neutron absorber materials in the nuclear industry.However,the addition of B4C particles deteriorates the weldability of B4C/Al MMCs,thus it is necessary to investigate the welding behavior of this composite.The microstructure and mechanical properties of welded joints of 30vol.％B4C/6061Al composites are investigated by using tungsten inert gas (TIG) welding and friction stir welding (FSW).The results of the tensile strength are shown as follows:FSW＞TIG welding(Al-Si filler metal)＞TIG welding(6061Al filler metal)＞TIG welding(6061Al-Mg filler metal)＞TIG welding(no fill metal).The reasons for the poor mechanical properties of TIG welding are mainly attribute to the generation of defects (such as pores,unevenly distribution of B4C particles and harmful phase) in welding.The FSW is identified as optimum welding method for B4C/6061Al composites,which can avoid the high temperature chemical reaction between the matrix metal and reinforcing particles,and producing fine recrystallized grains in the Al matrix,and the B4C particles are uniformly distributed in the weld joints.The tensile strength of the FSW joint is about 247 MPa,which is 85％ of the base material.
NETL
NSTL
万方数据
维普
