Study On Preparation Of Aluminum Matrix Composite Reinforced With Nano-SiC Particles And Charactering Their Physical Properties

With the development of the modern science and technology, especially the progress of aerospace and aircraft industries, more and more advanced materials which have excellent properties are desired. These properties such as lower density, high specifc strength and high fracture toughness are hoped, and the probability of utilization in high temperature, high pressure, high vacuum, intense corrosion or radiation harsh environment are expected. The requirement for light, strong and stiff materials has extended an interest in metal–matrix composites (MMCs) received substantial attention because of their improved strength, high elastic modulus and increased wear resistance over conventional base alloys during the last 20 years. Ceramics, e.g. boron, carbon, silicon carbide and alumina which have been produced in various forms such as continuos fibres, short or chapped fibres, whiskers and particulates or wires, e.g. steel or tungsten have been used as reinforcement in MMCs. Among these metal matrix composites, SiC particles reinforced Aluminum matrix composite are being considered by aerospace and automotive industries for several engine applications such as connecting rods, pistons, gear selector torks and cylinder liners because of their high-strength-to weight ratio. In this paper, the development of the Al matrix composite reinforced with SiC particles are summarized and the current are forecasted. Based on the reviews of the latest developments, a new idea was brought forward to prepare Al matrix composite reinforced with nano-SiC particles. The experiments could divideed primarily three steps: Preparation of nano-composite powder, making billets and sintering. The XRD,SEM and DTA methods are used to character the changes during the first stage of mixing composites power, good composite powders of 5,10,20volSiCp/Al are fabricated by the high energy mill. In order to improve the relative density of nano-SiC particle-reinforced Aluminum matrix composites, a process of pressing in high pressure (850Mpa) and moderate temperature (230oC) was added to the conventional preparation method of powder metallurgy technique. After sintering, the relative density of samples containing 5,10vol% of SiC reached 99.9%, and that of of 20vol%SiCp/Al reached 96.39%. Dramatic enhancements in strength and hardness for all the samples with nano-SiC reinforced Al matrix composite, the Yield strength of the 5, 10, 20%SiCp/Al are375, 440, 625Mpa separately. The mechanism of the reinforcement was analyzed using Orowan model, the differences between the results received by theory...