Synthesis and forming behavior of aluminum-based hybrid powder metallurgic composites
ZHENG Xigui1,2,Lü Ganglei1,2,ZHU Yonggang1,2
(1.Zhengzhou Institute of Technology, School of Mechanical Engineering, Zhengzhou 450064, China; 2.Henan
Provincial Digital Intelligent Equipment Engineering Research Center,Zhengzhou 450064, China)
Abstract:Aluminium-based metal matrix composites were synthesized from Al、TiO2 and Gr powder mixtures
using the powder metallurgy technique and their forming characteristics were studied during cold upsetting. The
powder preforms were pressed with a 40 kN hydraulic press with appropriate punches and dies, and then sintered
in an electric furnace at 590 ℃ for 3 h in an air atmosphere. The sintered preforms were subjected to incremental
compressive loads of 10 kN until cracks were found on the free surface. Axial stress (σz), hoop stress (σθ), mean
stress (σm) and effective stress (σeff) were calculated for all pre‐ forms, which are related to the axial strain (εz).The
densification behavior of the composites under axial strain (εz)and transverse strain was investigated.It is observed
that the addition of 5% TiO2 into the Al matrix increases σz, σθ, and σm. The addition of both TiO2 and Gr reinforcements
reduces the densification and deformation characteristics of the sintered preforms during cold upsetting.