Journal of Material Sciences & Engineering

Melt Infiltration Casting of Alumina Silicon Carbide and Boron Carbide Reinforced Aluminum Matrix Composites

Abstract

Ali Kalkanli, Tayfun Durmaz, Ayse Kalemtas and Gursoy Arslan

This paper discuss the effect of processing details such as particle size, sintering temperature, preform preparation, aluminum alloy characteristics and melt temperature on the final mechanical properties of ceramic phase reinforced metal matrix composites. Since alloy composition was determined as 7075 and 7085 optimum solutionizing and ageing temperatures were studied to determine maximum hardness values. For only 7085 alloy best solutionizing temperature is 465°C and for 7075 alloy the maximum hardness achived as 178 BHN after heat treatment at 475°C. Alloys were heat treated for recystallization after hot rolling grain size were measured as 100-120 μm for 7085 alloy matrix. Various sintering temperatures were used for preform preparation such as 1300-1450°C. In 85% Al2O3 reinforced 7085 Alloy based MMCs preforms sintered at 1450°C high hardness values were achieved as 545 BHN. Intermetallic phase was determined in 7075 and 7085 alloys selected as alloy matrix. Al2Cu intermetallic pecipitate (θ phase) was determined as dominant second phase after T6 heat treatment but highly expected phase in 7000 series alloys MgZn2 (η phase) was not determined by XRD and SEM analysis techniques due to ultrafine precipitate size and homogeneous distribution.