The Study On Thermal Analysis Technology Of Hypoeutectic Aluminum-Silicon Alloy

Due to their excellent castability and good mechanical properties, aluminum-silicon alloys are the most important and most widely used aluminum alloy. However, a unmodified alloy contains large brittle silicon flakes which greatly aggravate the mechanical properties, especially the plastic properties. The plastic properties usually improved by means of modification in industry.The methods evaluated the modification level in industry of China are always time-consuming, and low precision. A fast, high precision thermal analysis system has been developed in this research program. In order to establish thermal analysis models matching with the system, ZL101 and ZL104 alloys were modified by strontium or sodium in this paper, the model between modification level and characteristic parameter was established.ZL104 and ZL101 alloy were researched; the modifier is Al-10Sr or Na salt. When ZL104 was modified by Sr, if△T_EG is above 8℃, the modification level is five to six, and if△T_EG is lower than 5℃, the alloy is unmodified, the characteristic parameter△TEG (the depression of eutectic growth temperature between modified and unmodified alloy) and modification level agreed with S-style curve relationship.when ZL104 was modified by Na salt, if△T_EG is above 5℃, the modification level is five to six, if△T_EG is lower than 2℃, the alloy is unmodified, the characteristic parameter△T_EG and modification level agreed with polynomial curve relationship.when ZL101 was modified by Na salt, if△T_EG is above 5℃, the modification level is five to six, if△T_EG is lower than 3℃, the alloy is unmodified, the characteristic parameter△T_EG and modification level agreed with S-style curve relationship. Alloy is always refined and modified together in industry. The effect of Al-5Ti-B on hypoeutectic alloy which modified by Sr is also researched in this paper. Al-5Ti-B just changes the level of Sr in the melt but not the modification mechanism, so it didn't change the relationship between△T_EG and modification level.Finally, a database built by Visual C++ was established in the thermal analysis software. This database was used for memoring data and giving reference for later research.