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Research on the Alloying Design for High Strain Rate Superplastic Materials

高应变率超塑性材料合金化设计研究

基本信息

批准号：
01550550
负责人：
FURUSHIRO Norio
金额：
$ 1.6万
依托单位：
Osaka University
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 1990
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-01550550/
关键词：
Superplasticity Fine Grain Hihg Temperature Deformation

项目摘要

It has been expected that "High rate superplastic materials" will be developed for industrial applications. The Dorn-type equation for high temperature deformation suggests that strain rate can be increased if the grain size is decreased. This means that grain refinement can effectively establish high strain rate superplastic materials.It is well known that a high degree of grain size refinement will result from the addition of zirconium to Al-base alloys. Powder-metallurgical processing with rapidly solidified powders is also available for the improvement of superplasticity by both the refinement of the solidified structure and the maintenance of the stable fine structure of a 7475 Al alloy during recrystallization and deformation. Therefore, P/M 7475 Al alloys containing Zr up to 0.9 wt% were selected as candidate specimens. The objective of the present project includes the clarification of the role and the effective amount of Zr to obtain high strain rate superplastic materials. As a result, the addition of 0.3%Zr or more is effective in grain refinement of the P/M 7475 Al alloy. However, alloys containing 0.7 and 0.9 wt%Zr only show superplasticity at 793K. The optimum strain rate is shifted to a higher range with increasing Zr. The alloy of 7475 Al-0.9%Zr shows the maximum elongation of 900% at the remarkably high strain rate of 3.3x10^<-1> s^<-1>.The deformation mechanism of such high stain rate superplasticity will be discussed briefly, by considering the effect of the fine particles of Zr on superplastic behavior.

预计将开发出用于工业应用的“高倍率超塑性材料”。高温变形的多恩型方程表明，如果晶粒尺寸减小，则应变速率可以增加。这意味着晶粒细化可以有效地建立高应变率超塑性材料。众所周知，在铝基合金中添加锆会导致晶粒尺寸高度细化。采用快速凝固粉末的粉末冶金加工还可通过细化凝固组织并在再结晶和变形过程中维持 7475 铝合金稳定的精细结构来提高超塑性。因此，选择 Zr 含量高达 0.9 wt% 的 P/M 7475 铝合金作为候选样品。本项目的目标包括阐明Zr的作用和有效量以获得高应变率超塑性材料。因此，添加0.3％以上的Zr对于P/M 7475铝合金的晶粒细化是有效的。然而，含有 0.7 和 0.9 wt% Zr 的合金仅在 793K 时表现出超塑性。随着Zr 的增加，最佳应变率向更高的范围移动。 7475 Al-0.9%Zr合金在3.3x10^<-1>s^<-1>的极高应变率下表现出最大900%的延伸率。通过考虑Zr细颗粒对超塑性行为的影响，将简要讨论这种高应变率超塑性的变形机制。