Effect of cold upsetting process on mechanical properties of Al-TiO2-Gr powder metallurgy composites
Lü Ganglei1，2.，ZHU Yonggang1，2.，ZHANG Zhihui3.
（1.Zhengzhou Institute of Technology, School of Mechanical Engineering, Zhengzhou 450064, China；2.Henan
Engineering Technology Research Center, Zhengzhou 450064, China； 3.Luoyang Railway Information Engineer‐
ing School, Luoyang 471900, China）
Abstract：Using ball mill powder as raw material, Al+2.5%TiO2+2%Gr, Al+2.5%TiO2+4%Gr, Al+5.0%TiO2+
2%Gr, Al+5.0%TiO2+4%Gr aluminum-based composite materials were prepared by powder metallurgy method.
The compaction process was carried out in a 40 kN hydraulic press with a suitable punch and die, and then sintered
in an electric furnace. The sintered preform was subjected to an incremental compressive load of 10 kN until cracks
were found on the free surface. During the cold heading process, the composite material produced elongated grains
due to deformation. The upsetting process reduces the porosity in sintered samples. For the composites containing
2.5% TiO
2 and 2% graphite, the pores are closed and filled by reinforcements, and the number of pores after cold
upsetting is very small. The addition of TiO2 and graphite particles improves the strength and hardness of the com‐
posites. For the composites containing 5% TiO2 and 2% graphite particles, the maximum hardness value 36.14HRB
is obtained.
2023, Vol. 33 
