Microstructure and Mechanical Properties of Al2O3 / A336 Compsite by Low Pressure Infiltratrion.

摘要

The ceramic fiber/whisker reinforced aluminum matrix composites have a considerable potential for providing light components exhibiting high specific strength with high specific stiffness excellent wear resistance, low thermal expansion and improved high temperature properties as compares with the conventional materials. So they have many applications such as automotive parts, sports goods, robot parts, electrical parts and so on. However, it was considered difficult to use some of them in the civil industry because of the high cost of the reinforcement and processing [1] [2]. Alumina reinforced Al-alloy matrix composite that has well wear resistance and this composite can use the material of any parts to need high wear resistance such as cylinder bore, and optimum combination of pistons and piston ring [3]. The casting processes are recognized to be the most advantageous because of their high productivity and formability. High-pressure infiltration is one of the casting processes used for the fabrication of MMCs, but it has some disadvantages such as high cost arising from the preparation of preforms and large scale facilities for high pressure infiltration [4]. Low pressure infiltration process (LPI) has the advantage of being semi-automatic and thus reducing labor costs as well as obtaining a better casting quality and a higher yield. Cost of LPI is lower than that of squeeze casting and that the process provides a better quality than gravity casting [5]. In spite of its many advantages, LPI process has not yet been fully appreciated and as used as widely as it should [6].