Influence of Heat Extrusion Process on Primary Si Phrase in Hypereutectic Al-Si Alloy

The influence of preheat temperature to the size of primary Si phrase of hypereutectic Al-Si X alloy produced by Spray-forming is concerned, the materials' microstrucature which extruded under the same temperature but different extrusion ratio are compared. The various effect of atomizing gas to melting metal and extrusion ratio to the primary Si phrase are discussed and the possible reasons which might cause microcracks are analyzed.