Effect Of The Content Of Cu On The Solidification Characteristics Of Al-Cu Alloys

High-strength cast aluminum-copper alloy (hereinafter referred to as Al-Cualloy) has good integrated mechanical properties, such as ductility, toughness,bearing capacity, machinability and plating, etc. In recent years, Al-Cu alloys aremainly used in construction, transportation, electricity, aerospace and otherindustries, particularly in the aerospace and aircraft manufacturing field toachieve the "Casting instead of forging". The high-strength characteristics of Al-Cu alloys can be fully brought out. However, Al-Cu alloy has wide crystallinetemperature range and casting is prone to appear hot cracking, shrinkage andother casting defects. These defects increased the casting difficulty of Al-Cualloys. The copper content in Al-Cu alloy is an important factor of influencingthe solidification characteristics. Therefore study the solidification characteristicsof different Cu content has important theoretical and practical significance.In this paper, single spiral sample test method and casting alloysolidification properties analyzer are used to measure alloy hot cracking tendency,thermal stress and linear shrinkage, study the effect of copper content on theproperties of aluminum-copper alloy solidification.The research results show that mobility decreased first and then increasedwith the content of copper increased; when the copper content is10%, the alloyis preferably flowability. Fluidity rises upward trend with the pouringtemperature. Degassing treatment can also significantly improve the liquidity ofAl-Cu alloy. When the copper content of5.5%and the temperature dropped to550℃, hot tearing tendency largest, most prone to hot cracking. When thetemperature is300℃, the thermal stress decreases and then increaseswithcopper content, the copper content is5.0%when the minimum value of thermalstress. When the content of copper is10%, the total maximum aftersuperposition of tensile stress and compressive stresses is19.5MPa. The linearshrinkage of Al-Cu alloy decreases first and then increases with copper content increasing, reached the minimum at5%.By selecting the right ingredients, improving the casting mould process andpouring conditions, adjusting the casting structure, preventing the casting thermalcracking effectively, reducing thermal stress and linear shrinkage, improve thequality of castings.