Research On Forming Of The Soleplate Using SIC Particle-reinforced Aluminum Matrix Composites

In this paper, the materials of SiC particle-reinforced aluminum matrix composites are used to make the soleplate. And the stirring processing of composites is studied. The wear resistance, mechanical properties and microstructure of the composites are measured through the frictional wear test, hardmeter, universal tensile testing and microscope followed by the relevant optimal forming factors analyzed.The special devices including the resistance wire heating furnace and the stirring bar with two rows of blades are designed. The rotating speed of the stirring bar are controlled by electric motor which is fixed on the rocker arm drilling machine.To increase the wettability of the interface between SiC and Al, SiC particles is pretreatmented. The main specific processes are: 10%HF immersed and sintered with 800℃high temperature. The surface feature of composites is analyzed by the scanning electronic microscope (SEM). It indicates that after the pretreatment the surface of composites is clean, and the impurities are eliminated. 30 groups of soleplates are fabricated with different rotating speed, temperature, stirring time and different dimensions and volume fraction of SiC particles. To obtain the high intensity and hardness of the soleplate, the T6 heating treatment is carried.The soleplates made of composites of 7μm10Vol% SiCp/Al stirred 60 minutes under the temperature of 700℃obtain the optimal wear-resistance. The mechanical properties test shows that the mechanical properties achieve the design requisite with tensile strength 359.46MPa and hardness HV115.97. The microsruce of the composites which is measured by the scanning electronic microscope indicates that SiC particles are distributed on the aluminum alloy without conglomeration, and the property of the interface cohesion is excellent.It indicates that the wear amount and rate of composites increase with the sliding rate, and firstly decrease then increase with the increase of the percentage of the SiC particles. The frictional coefficient has the same behavior with the wear amount. Compared with the pure 2A50 aluminum alloy, the wear amount of soleplates made with composites decreased by 57%~69%. The dominant wear mechanism is abrasive wear behavior, wich is mixed with slight adhesion and oxidation. But the extent of the two wear mechanism is different with the change of the volume fraction of the SiC, forming coefficients and frictional conditions.