Research On Preparation Process And Wear Resistance Of Al-Si Powder Metallurgy

Aluminum powder metallurgy materials were prepared by liquid phase sintered powder metallurgy. By using density test, hardness test, wear test, metallographic test and other experimental testing methods, the pressing and sintering parameters, adding elements and different SiC volume fraction on the microstructure and properties of Aluminum powder metallurgy were studied. The experimental results showed that: aluminum compaction's density is 2.78 g/cm3 when pressure at 600 MPa, the author of equations in according with Kawakita Kimio are more suitable for fitting of aluminum pressing, When the pressing pressure is small or press speed is large prolonged the pressing time conducive to compact density, More than 200 mesh coarse powder is more fluidity and formability, Silicon is conducive to improve to a certain extent, but it decreases the density of pressed aluminum powder; The optimum sintering process of eutectic Al-Si alloy is 570?×1h, with the sintering temperature rise hardness increases at 560? get to maximum, but the organization is uneven at this temperature, When at 570? the microstructure completely transformed into a uniform eutectic structure; Sintering time have greater impact on microstructure but little effect on the hardness, Eutectic reaction of aluminum silicon powder melting the solid phase, and then precipitated into Eutectic structure; Alloying elements on hardness and wear resistance greatest impact is copper, the best overall performance's chemical composition (wt.%) is Al-18Si-6Zn-4Cu-1.5Mg, It's mainly made up of primary silicon, Al2Cu and Alo.71Zno.29 and other phase, the wear mechanism is abrasive wear and fatigue wear; Increasing silicon carbide content has little effect on the pressing density but is able to promote densification, When 5-15 vol.% of SiC hardness value is large and 15-30 vol.% have good wear resistance, The wear mechanism is abrasive wear and peel wear with emery sandpaper on frictional wear.