Si含量对高强高韧7050铝合金组织和力学性能的影响  

Influence of Si Contents on Microstructures and Mechanical Properties of High Strength and Toughness 7050 Aluminum Alloys

作　　者：张克伟[1] 佘欢[2] 刘宏亮[2] 疏达[2] 王俊[2] 

机构地区：[1]东北轻合金有限责任公司,哈尔滨150060 [2]上海交通大学金属基复合材料国家重点实验室,上海200240

出　　处：《上海交通大学学报》2013年第11期1712-1716,共5页Journal of Shanghai Jiaotong University

基　　金：国家重点基础研究发展规划(973)项目(2012CB619505)

摘　　要：通过熔炼制备8种不同杂质Si含量的7050铝合金，研究了Si含量从0．033％～0．491％的变化对7050铝合金组织和力学性能的影响规律．结果表明：当Si含量增加至0．134％时，合金铸态组织中出现明显的粗大富Si杂质相，并且随Si含量增加，富Si杂质相含量增多；粗大富Si杂质相在均匀化退火、热挤压以及固溶处理过程中都难以溶解，残留在时效态合金组织中；当Si含量增加至0．134％时，时效态合金的室温拉伸强度和塑性明显提高；在Si含量高于0．344％后，Si含量的增加使合金的室温拉伸强度、塑性和断裂韧性都显著降低．为获得最佳的室温强度和塑性，7050铝合金的Si含量应控制在0．121％～0．134％，但要获得更好的断裂韧性，需进一步降低合金中Si含量．Eight kinds of 7050 aluminum alloys with different Si contents have been prepared by cast. The influence of Si contents from 0. 033 % to 0. 491 % on microstructures and mechanical properties has been in vestigated. The results show that significant coarse Si-rich impurity phase has been found in as-cast micro structures when Si content is increased to 0. 134%, and the content of this phase is increased with Si content increasing. The coarse Si-rich impurity phases are insoluble during homogenizing annealing, hot ex trusion and solution treatment, and remain in aged microstructures of alloys. The aged alloy with 0. 134 Si has the highest tensile strength and plasticity at room temperature. The strength, plasticity and fracture toughness reduce significantly when Si content is higher than 0. 344 %. Si content should be controlled in the range of0.121% to0.134% to get the best strength and plasticity. To obtaina better fracture toughness, the Si content in the alloy should be further reduced.

关 键 词：7050铝合金 SI含量 力学性能 

分 类 号：TG146.2[一般工业技术—材料科学与工程]