Aluminum-matrix composites (AMC) produced by mechanical stirring method possess excellent properties of higher strength/weight ratio, good wear resistance and good corrosion resistance. However, the stirring procedure often results in non-uniform distribution of reinforcement particles (e.g., SiCp) in the aluminum melt. Thus the AMC parts cast domestically by such a method always show the worse mechanical properties then those parts cast foreignly by the same method. This study aims to search for the best mechanical stirring design composed of such a mixer that produces a well uniform distribution of the reinforcement particles in aluminum melt. By means of the water simulation experiment, the flow and distribution of the particles in the liquid at predetermined velocities for various stirring designs, including three types of stirring bars (a bar with a smooth surface, a bar with six straight grooves, and a bar with a spiral groove) and four blade disk forms (a disk with six straight teeth, a disk with six straight teeth plus six short pillars bellow, a right-hand spiral furrow disk, and a left-hand spiral furrow disk), has been observed and analyzed thoroughly. The simulation experiment utilized many small pieces of cloth as the reinforcement particles to be stirred in the water tank. The video camera has also recorded all the flow situations of these cloths in the water made by the above-mentioned mixers. The result shows that a very uniform distribution of cloths in the liquid has been obtained by using the mixer composed of a stirring bar with a smooth surface matched a blade disk with six straight teeth plus six short pillars below or of a stirring bar with a spiral groove matched a right-hand spiral furrow blade disk.
Aluminum-matrix composite Mechanical stirring method