| Because of its small density,high specific strength and high specific stiffness,aluminum alloy was called"green"nonferrous alloy in industry.With the attention of energy and environmental problems,the research and application of aluminum alloy materials have been developed rapidly.Al-Si alloy is one of the most widely used alloys in casting aluminum alloy,which has excellent casting properties,such as good fluidity,good air tightness,low shrinkage and small hot cracking tendency.The Al-Si alloy occupied a very important position in industrial production,and most have been used in aerospace,military,agriculture and other fields,at the same time,Al-Si alloy was also used in the metal structures of construction,household items and sporting goods.This paper added modified Cu-TiN powders into ZL101A alloy,The results show that the modified powder can improve the morphology of eutectic silicon,refine the microstructure and improve the mechanical properties,wear resistance and corrosion resistance of the alloy.Adding different amounts of modified Cu-TiN powders to ZL101A melt,when the powder was added in an amount of 0.15%,the ZL101A alloy had the best microstructure and mechanical properties.Its average grain radius reached the minimum which was about90.30?m and the grain size decreased by 54.3%.Eutectic silicon was changed from Unevenly distributed Long rod or needle shaped to Circular point evenly distributed in the crystal.In addition to the elongation rate,the other mechanical properties of ZL101A was improved,the tensile strength increased by 7.57%,the elongation decreased by a factor of 24.68%,the Brinell hardness increased by 24.36%,and the weight loss rate was decreased to about0.357%.When the powder was added in an amount of 0.20%,the corrosion resistance was the best.The corrosion products were Al2O3·3H2O,AlO?OH?and?-Al?OH?3.Corrosion forms were mainly pitting and intergranular corrosion.The strengthening and toughing mechanism of modified Cu-TiN powders in melt ZL101A alloy shows that:In the solidification process the modified Cu-TiN powders increased the nucleation,refined grains,and play the role of fine grain strengthening;At the same time,as the second phase particle distribution in the?-Al matrix,enhanced its mechanical properties and corrosion resistance. |
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