Of Al-zro <sub> 2 </ Sub>, Of Al-zro <sub> 2 </ Sub>-b, Of Al-zro <sub> 2 </ Sub>-c System In Aluminum Matrix Composites Friction And Wear Properties Of

In this article, the AI-ZrO2, Al-ZrO2-B and Al-ZrO2-C systems aluminum matrix composites were successfully fabricated by means of the Exothermic Dispersion (XD) method. The curve of wear mass loss and friction coefficient were tested by the abrasive-wear tester. According to the SEM morphologies and EDS images of wear surface and wear subsurface optical morphologies, the influence of the sliding distance, sliding velocity, load and the reinforcement volume fraction on the the friction and wear properties of the composites was analyzed both at ambient and elevated temperature. At last, the wear mechanism of the composites was studied refer to the basic theory of wear.At ambient temperature, the wear resistance of the composites fabricated by AI-ZrO2 system was the best among the Al-ZrO2-X system and there were some fractures vertical to sliding direction on the wear surface. The Al3Zr rods were endured bent stress and the crack nucleuses were produced in them. When the rods were near to wear surface, they would crack and become the abrasive grains to enhance wear. Among the combustion results, the fine ZrB2 and ZrC grains were distributed uniformly in matrix and had good use to improving the wear resistance of the composites. When the reinforcement volume fraction reached 30%, the wear property of the composites was better than that when the reinforcement volume fraction was 20%.The relation between wear mass loss and sliding distance was linear for the Al-ZrO2-X system. The mean of the friction coefficient changed a little and the fluctuation range of the AI-ZrO2 system was the least.The wear mass loss increased along with the load for the Al-ZrO2-X system. At ambient temperature, the friction coefficient of the Al-ZrO2 system increased a little and the fluctuation range decreased first and then became larger along with load when load got to 80N, while that of Al-ZrO2-B and Al-ZrO2-C system decreased gradually. At the temperature of 373K, the friction coefficient of the AI-ZrO2 system increased while that of the other two systems decreased, and all the fluctuation range decreased. At the temperature of 473K, the friction coefficient of the Al-ZrO2 system was not steady very much, and the experiment stopped when the sliding distance got to 100m because of the serious wear of the composite. This indicated that the addition of the B and C was good for the improvement of the wear property.The disciplinarians of wear mass loss with sliding velocity were resemble for the Al-ZrO2-X system and the peak values of them corresponding to the sliding velocity would move to the lesser sliding velocity with rising of wear test temperature. The friction coefficient decreased along with the increase of the load at ambient temperature, but it increased first and then decreased at the temperature of 373K, and it changed hardly at 473K.There were three microstructure styles such as 1. segregated Al2O3 grains and Al3Zr rods, 2. uniformly grains and rod-like Al3Zr,3. uniformly grains in Al-ZrO2-X system. When the microstructure style of the composites was the first, the abrasive grains wear would take the role in the wear and the others such as oxidation and adhesion were subordinate to it. In the second, the abrasive grains wear would become lesser and adhesion wear become strengthener. In the third, the adhesion wear would be main wear mechanism of the composites.