Fundamental Research on Very High Strain-rate-deformation in Hard-forming Materials of Composites, Intermetallics and Ceramics.

复合材料、金属间化合物和陶瓷硬成形材料中极高应变率变形的基础研究。

基本信息

批准号：
01550537
负责人：
TANIMURA Sinji
金额：
$ 1.79万
依托单位：
University of Osaka Prefecture
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1989
资助国家：
日本
起止时间：
1989 至 1991
项目状态：
已结题

项目摘要

The development of new materials, through recent advances in technology, has led to new forming processes in hard-forming materials of composites, intermetallics and ceramics. One of them is superplatic forming, which showed both large elongations and high strain-rate sensitivities, has been limited in use because of its lower productive rate than an industrial one. On the ther hand, it was reported that some materials exhibited a high strain-rate sensitivity at extremely high strain rates over 1 s^<-1>. In this subject, high strain-rate deformation properties in hard-forming materials of composites, intermetallics and ceramics are investigated in a wide strain-rate range and temperatures. Low strain rate tensile tests (10^<-4>-1 s^<-1>) were performed with an instron machine, and intermediate strain rate tensile tests (1-300 s^<-1>) were performed with the hydraulic tensile testing machine, and the dynamic tensile tests (400-4000 s^<-1>) were performed using a split Hopkinson pressure … More bar system which incorporates a specific attachment. A large elongation of about 600% was obtained both in a Si_3N_<4w>/Al-Mg-Si composite at an initial strain rate of 2 x 10^<-1> s^<-1> and also in a Si_3N_<4p>/Al-Mg-Si composite at an extremely high strain rate of 2 s^<-1>. Furthermore, large elongations of more than 1000 % were obtained in the mechanically alloyed aluminum IN 9021 (Al-4.0wt%Cu-1.5wt%Mg-1.1wt%C-0.8wt%O) deformed at extremely high strain rates from 10 to 100 s^<-1>. The maximum elongation of 1250 % was recorded at 50 s^<-1> and 823 K. The optimum strain rate range in these new advanced aluminum alloys is three or four orders of magnitude faster than for the best of the conventional commercial alum inum alloys, such as Supral or 7475 alloys. Large elongations of more than 500 % are obtained at high strain rates between 5 and 100 s^<-1> for a mechanically alloyed 15 vol % SiCp/IN9021 aluminum composite tested at 823 K. It is clear that superplastic strain-rate increases with decreasing of grain size. From this relationship, the refinement of grains or sub-grains size is one of necessary and important to obtain the high strain-rate superplasticity. In future it might be possible that the predicted range of superplastic behavior in nano-phase materials by Sherby and Wadsworth would be achieved in mechanical alloyed materials with an optimum microstructural control. Less

通过技术的最新进展，新材料的开发导致了成型材料，金属间和陶瓷的艰苦形成过程。其中之一是超铂形成，它显示出较大的伸长率和高应变率敏感性，由于其生产率低于工业效率，因此在使用中受到限制。据报道，某些材料以超过1 s^<-1>的极高应变速率暴露了高应变率灵敏度。在这个主题中，研究了复合材料，中间体和陶瓷的高应变率变形特性，以广泛的应变率范围和温度进行。使用仪器机进行低应变率拉伸测试（10^<-4> -1 s^<-1>），并使用水解性张力测试机进行了中等应变率的拉伸测试（1-300 s^<-1>），并使用压力进行了较大的压力。在SI_3N_ <4W>/al-MG-SI复合材料中，以2 x 10^<-1> s^<-1>的初始应变速率以及在极高的2 s^<-1>的极高的应变率下，以2 x 10^<-1> S^<-1>的初始应变速率以及在SI_3N_ <4p>/al-MG-SI复合材料中获得了大约600％的伸长率。此外，在9021（Al-4.0wt％CU-1.5WT％MG-1.1WT％C-0.8WT％O）中，在机械合金合金的铝中获得了超过1000％的较大伸长率，该伸长率从10到100 s^<-1>>> 100>>>> 100>>>>>> 100>>。在50 s^<-1>和823 K处记录了1250％的最大伸长率。这些新的晚期铝合金的最佳应变率范围比最佳的传统商业校友合金（例如Supral或7475 Alloys）快三到四个数量级。对于在823 K下测试的机械合金合金15 vol％SICP/IN9021铝复合材料的高应变率以5至100 s^<-1>之间的高应变速率获得的较大伸长率。从这种关系中，对于获得高应变率的超塑性性，晶粒或亚粒大小的细化是必要和重要的之一。未来，Sherby和Wadsworth的纳米相材料中预测的巨型行为可能会在具有最佳的微结构控制的机械合金材料中实现。较少的