摘要
浇注温度和温度梯度是控制材料凝固行为的重要因素,研究了不同温度梯度下浇注温度对ZL205A合金组织和性能的影响。结果表明,随着浇注温度的升高,θ相由连续分布的条状转变为颗粒状,对基体的割裂减少,且总体残余量减少,分布也变得相对均匀规则。由壁厚差引起的温度梯度对θ相形貌和径向成分梯度产生一定影响,降低温度梯度能促进Cu原子在基体中的固溶度,从而增加固溶强化效果。合金的充型能力随浇注温度的升高(680~740℃)呈现出先增加后降低的趋势,随壁厚的增加(5~25 mm)而持续增加。当壁厚为8~10 mm时,合金的抗拉强度随浇注温度基本呈线性变化;而壁厚为12~18 mm时,抗拉强度在205 MPa左右波动。在同一浇注温度下,壁厚(8~18 mm)对该合金的铸态力学性能的影响不太明显。
The effect of pouring temperature and temperature gradient on the microstructure and properties of ZL205A alloy was investigated. The results indicate that, with the increase of pouring temperature, the θ-（Al2Cu） phases converte from long strips into particles form, which lower the cut apart trend on matrix, and whole residual amount reduces. The distribution of θ-phases also becomes relatively uniform and regular. The temperature gradient caused from wall thickness difference has certain impact on the θ-phase morphology and the composition gradient in radial direction, and reducing temperature gradient can promote the solid solubility of Cu atoms, so as to enhance the effect of solid solution. The fluidity first increases and then reduces with arising pouring temperature, and presents the trend of continuous improvement with the increase of thickness. When the thickness is 8 mm and 10 mm, tensile strength basically is linear-changing versus pouring temperature, but its varying range is small and maintaines in 205 MPa when the thickness is 12 mm and 18 mm. At same pouring temperature, the influence of thickness on the as-cast tensile strength is unobvious.
出处
《铸造技术》
北大核心
2017年第6期1410-1415,共6页
Foundry Technology
基金
有色金属先进加工与再利用国家重点实验室开放基金项目资助(1302GKDA015)
甘肃省科技重大专项计划资助(SKL1303)
关键词
ZL205A
浇注温度
壁厚
温度梯度
流动性
微观组织
力学性能
ZL205A alloy
pouring temperature
thickness
temperature gradient
fluidity
microstructure
mechanical properties
