The Effect Of Melt Treatment On Shrinkage-expansion Of Aluminum Alloy

Al-Si alloys have a low density, high strength, wear-resistant, good heat resistance, etc., so they are widely used in military, civilian areas, specially applied to the aviation and aerospace fields. However, the shrinkage of Al-Si alloy has been became a concern, for the alloy solidification of volume change is 6% and the defects such as shrinkage cavity and porosity are caused by solidification shrinkage. As we know we can use melt treatment to eliminate these defects effectively. Thus the purification, refinement and modification of hypoeutectic Al-Si alloy is becoming the focus of attention, many scholars have studied.This paper studies ZL101 alloy and we obtain the macrostructure, microstructrue and the corresponding density through the different melt treatment process. Therefore, this article studies that the melt treament methods have an impact on the shrinkage characteristics of aluminum alloy, through adding Al-5Ti, Al-5Ti-B, Na salt, Al-10Sr and Al-10RE to change the melt treament and combining with the melt process under different sample density and the corresponding solidification organization. In this paper we discuss the melt treatment process which has an effect on the organization and the density of ZL101 alloy, the results are more important theoretical and practical significance. The main contents:Studied the contraction of Alloy Solidification Shrinkage generated, the mechanism of the defects such as shrinkage, contraction of the liquid aluminum alloy, solidification and solid-state contraction and the phenomenon of contraction have osteoporosis, the causes of defects such as shrinkage cavity was discussed on the aluminum alloy commonly used refinement and metamorphic method described to obtain a suitable melt-processing methods;Air tightness test in accordance with the requirements of the sample box is designed to be simple to determine the sample mold design, through the addition of different agents and the grain refinement Modificator different melt-treatment methods, the development of the ZL101 alloy smelting, casting experiment of experimental methods of analysis of a brief;Melt-treatment on the purification of high-performance, refined handling, such as modification of the macro-ZL101 alloy, the microstructure and the effects of density, through the microstructure analysis and experimental results show that gastightness: ZL101 alloy refined to deal with so well-developed dendritic primaryα-Al grain refinement into a small equiaxed grains, to allow inter-dendritic liquid alloy full feeding, so that modification or ZL101 alloy strip of needle-like eutectic Si refinement into a worm-like or round point and is conducive to feeding liquid alloys through the interaction of thinning and degeneration of the ZL101 alloy density better; Finally the mechanism of modification of complex which impact on the Si-phase mechanism and the densification of aluminum alloy melt treatment of the impact of the mechanism are discussed and analyzed.