Mechanical properties of aluminum/quartz particulate composites cast using metallic and non-metallic chills

Manufacturing and Properties of Quartz (SiO2) Particulate Reinforced Al-11.8%Si Matrix Composites

“…Consequently, these residual stresses would probably contribute for the brittle nature of the composites. It should be noted that the compressive strength of the quartz particulate dominates which is more than the tensile strength of the LM6 alloy matrix and hence the tensile strength decreases with more amount of addition of quartz particulate afact which is well supported is well supported and evidenced from the literature citation (Rizkalla and Abdulwahed, 1996;Seah, et al, 2003).…”

“…Preliminary studies showed that the contact between molten aluminum and silica-based ceramic particulates have destroyed completely the second phase microstructure, due to the reduction reaction which provokes the infiltration of liquid metal phase into the ceramic material (Mazumdar, 2002). Previous works carried out by using continuous silica fibers as reinforcement phases in aluminum matrix showed that even at temperatures nearer to 400 0 C, silica and aluminum can react and produce a transformed layer on the original fiber surface as a result of solid diffusion between the phases and due to the aluminum-silicon liquid phase formation (Seah et al, 2003). The organizations and companies that are very active in the usage of MMCs in Canada and United States include the following (Rohatgi, 1993) India also has substantial activity in PM and cast MMCs.…”

“…The increase of closed pores content with increasing quartz particulate content would create more sites for crack initiation and hence lower down the load bearing capacity of the composite. The fluctuation maybe due to the non-uniform distribution of quartz particulates, due to experimental errors and also depends on the cooling rate of the castings (ASTM, 1991;Seah, et al, 2003). When particulates increase, particles are no longer isolated by the ductile aluminum alloy matrix, therefore cracks will be not arrested by the ductile matrix and gaps would propagate easily between the quartz particulates.…”

“…This phenomenon is shown in Figure 10. The problem on interfacial bonding between the particulate quartz and the matrix during the solidification of composites can be ignored because the phenomena of cracking occurs only in a small part of the surface (Seah, et al, 2003). In contrast, when the content of quartz was increased (30%), interfacial bonding concept would be an important phenomenon because the surface cracking will be distributed on the surface of the parts.…”

Electrical Conductivity and Corrosion Performances of In Situ and Ex Situ AA7075 Aluminum Composites

“…Due to these superior properties, aluminum alloys are used in the production of metal-matrix composites. The most widely used ceramic reinforcement materials in the production of aluminum composite materials (ACMs) are SiC [5], Al 2 O 3 [6], SiO 2 [7], Si 3 N 4 [8], AlN [9], ZrB 2 [10], TiB 2 [11], B 4 C [12], and TiC [13]. B 4 C is an attractive reinforcement material used in production of aluminum composites having low density, high rigidity and thermal stability [14].…”