权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Development of Aluminum Alloys with High Strength and High elasticity Controlled Structurally by Solidification Processing.

凝固加工组织控制高强度高弹性铝合金的开发。

基本信息

批准号：
04402048
负责人：
KAMIO Akihiko
金额：
$ 21.38万
依托单位：
Tokyo Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (A)
财政年份：
1992
资助国家：
日本
起止时间：
1992 至 1994
项目状态：
已结题

项目摘要

On the Al-Li and the Al-Mg alloys composites reinforced with SiC whiskers fabricated by the squeeze casting, the preparation technique was established and the relation between the properties and the structure control was clarified for the purpose of the development of aluminum alloys with the low density, high strength and elasticity.It was found that the low concentration region of Li or Mg shaped along the infiltration path of matrix alloy melts in the composites was formed during squeeze casting by the reaction between the Li or Mg solute atom in aluminum matrix melts and the SiO_2 presented in the SiC whisker preform. Sound composite ingots without the Li or Mg depleted region was obtained by using the fabrication method specially designed so as to through out of the depleted region for outside of composite ingots.The remarkable age hardening of the SiCw/Al-Li alloys composites was obtained, despite of no or slight age hardening of the other age hardenable aluminum alloys composite … More s. The prominent age hardening of Al-Li based alloy composites was obtained by the precipitation of metastable delta' and/or T_1 phases. The T_1 phase in the composites was precipitated preferentially on the dislocations of high density generated during quenching after the solution treatment. In the SiCw/Al-Li alloys composites, the elastic modulus and yield strength were increased linearly with increasing the SiC whisker volume fraction.In the SiCw/Al alloy composites, the tensile yield strength was decreased and the compressive yield strength was increased by the tensile residual stress induced during cooling from the solution treatment temperature. The magnitude of the averaged tensile residual stress measured by X-ray diffraction method in the composites was strongly dependent on the yield strength of the matrix in composites. The tensile yield strength of the composite restored to room temperature after cooled into liquid nitrogen temperature was significantly increased by the double effects due to both the decrease of the tensile residual stress and the increase of the average dislocation density in the matrix of the composite.In the Al-Mg alloy composite contained a large amount of the SiO_2 phase, the good connection at the interface caused by the formation of the MgAl_2O_4 as the main reaction phase at the whisker/matrix interface was achieved. The control of the connecting strength at the interface and the improvement of the yield strength for the composite materials are obtained by the control of the kind of the interface reaction products and the thickness due to the proper choice of the amounts of SiO_2 phase. Less

针对挤压铸造制备的SiC晶须增强Al-Li和Al-Mg合金复合材料，建立了制备工艺，明确了性能与组织控制的关系，以开发低密度、高强度、高弹性铝合金。复合材料是在挤压铸造过程中通过铝基熔体中的Li或Mg溶质原子与SiC晶须预制件中存在的SiO_2之间的反应形成的。通过使用专门设计的制造方法，使复合材料锭外部穿过贫化区，获得了没有贫锂或镁区的良好复合材料锭。尽管其他可时效硬化铝合金复合材料没有或轻微时效硬化，但SiCw/Al-Li合金复合材料获得了显着的时效硬化。 Al-Li基合金复合材料显着的时效硬化是通过亚稳态δ'和/或T_1相的析出获得的。复合材料中的T_1相优先在固溶处理后淬火时产生的高密度位错上析出。在SiCw/Al-Li合金复合材料中，弹性模量和屈服强度随着SiC晶须体积分数的增加而线性增加。在SiCw/Al合金复合材料中，从固溶处理温度冷却过程中产生的拉伸残余应力导致拉伸屈服强度降低，压缩屈服强度增加。通过 X 射线衍射法测量的复合材料中的平均拉伸残余应力的大小很大程度上取决于复合材料中基体的屈服强度。由于复合材料基体中残余拉应力的降低和平均位错密度的增加的双重作用，冷却至液氮温度后恢复至室温的复合材料的拉伸屈服强度明显提高。实现了晶须/矩阵接口。通过适当选择SiO_2相含量来控制界面反应产物的种类和厚度，从而实现对界面连接强度的控制和复合材料屈服强度的提高。较少的