(1. 哈爾濱工業(yè)大學(xué)材料科學(xué)與工程學(xué)院，哈爾濱 150001；
2. 哈爾濱工業(yè)大學(xué)機(jī)電工程學(xué)院，哈爾濱 150001)
摘 要: 采用ProCAST軟件模擬了A356.2鋁合金汽車輪轂在局部增壓鑄造技術(shù)下的充型和凝固過程，探究了鑄件的溫度場(chǎng)、缺陷分布和應(yīng)力場(chǎng)。結(jié)果表明：鑄件基本符合順序凝固，但是部分區(qū)域出現(xiàn)了熱節(jié)；縮松、縮孔缺陷主要分布在輪輻與輪輞交界處、輪輻與中間轂交界處以及輪輞某些區(qū)域；合適的澆注溫度、模具溫度以及局部機(jī)械加壓可以有效地減少缺陷；等效應(yīng)力大小由熱應(yīng)力與機(jī)械應(yīng)力共同決定。正交試驗(yàn)優(yōu)化后的壓鑄參數(shù)為：澆注溫度tpouring710 ℃，上模溫度tupper die340 ℃，邊模溫度tside die360 ℃，下模溫度tlower die400 ℃，風(fēng)壓0 MPa，機(jī)械壓力1.4 MPa。在此條件下由試驗(yàn)獲得的輪轂缺陷最少，力學(xué)性能最好。
關(guān)鍵字: A356.2 鋁合金；局部增壓鑄造；數(shù)值模擬；溫度；壓力
（1. School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China;
2. School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001, China）
Abstract:ProCASTsoftware was used to simulatethe filling and solidification process ofA356.2 aluminum alloy automobile hub through local pressurizationcasting technology, and temperature field, defects distribution and stress field were investigated. The results show that the solidification is basically in sequence, but thermal centers appear at some regions.Shrinkageporosities defects are mainly distributed in the spoke/rim junction, spoke/center hub junction, and the partial region of rim. Proper pouring temperature, moulding temperature andlocal mechanical pressurization can eliminate the defects effectively. The effective stress is codetermined by the thermal stress and mechanical stress.The die-casting parameters optimized after the orthogonal test are as follows: pouring temperature of 710 ℃, upper dietemperature of 340 ℃, side die temperature of 360 ℃,lower die temperature of 400 ℃, wind pressure of 0 MPa, and mechanical pressure of 1.4 MPa.Under the optimized conditions, the hub obtained from the test has the least defects and the best mechanical properties.
Key words: A356.2 aluminum alloy; localpressurizationcasting; numerical simulation; temperature; pressure
