表面机械滚压对Zr-4合金组织和力学性能的影响
Effect of SMRT on Microstructure and Mechanical Properties of Zr-4 Alloy
辛超 1徐巍 1孙巧艳 1肖林 1孙军1
作者信息
- 1. 西安交通大学金属材料强度国家重点实验室,陕西西安710049
- 折叠
摘要
采用表面机械滚压对退火态Zr-4合金进行表面纳米化处理并对其微观组织和力学性能开展了系统研究.滚压处理在Zr-4合金表面形成纳米/超细晶及变形层的厚度与滚压道次、每道次滚压深度有关;对Zr-4合金优化后的滚压参数为每道次滚压深度40μm、滚压8道次,获得从表面到心部由纳米晶、超细晶、变形组织和心部原始粗晶连续梯度变化的组织形貌,其纳米/超细晶层的厚度约为1 00 μm,变形层的厚度约为300 μm.Zr-4合金经滚压处理后,表层显微硬度显著提高;屈服强度和抗拉强度分别为352和600 MPa,各提高了7％和9％,延伸率略有降低.用混合法则计算了Zr-4合金表面滚压处理后的屈服强度,与实验值吻合.
Abstract
The microstructure and mechanical properties of as-annealed Zr-4 alloy subjected to surface mechanical rolling treatment (SMRT) were investigated.The effect of rolling passes and rolling depth per pass on the thicknesses of NG (nano grain)/UFG (ultrafine grain) layer and deformed layer in the SMRTed Zr-4 alloy were studied.The optimized process parameters are 8 passes and depth of 40 μm per pass.A gradient microstructure consisting of a NG/UFG layer of 100 μm in thickness,a deformed layer of 300 μm in thicknesses and a CG (coarse grain) layer are produced in the SMRTed Zr-4 alloy from the treated surface to the matrix.The microhardness on surface significantly increases due to SMRT.The yield stress and ultimate tensile strength of SMRTed Zr-4 alloy are 352 and 600 MPa,increased by 7％ and 9％,respectively.And the elongation is slightly reduced.The yield strength 362 MPa calculated by the rule-of-mixture is similar to the experimental value.
关键词
Zr-4合金/表面纳米化/力学性能/表面机械滚压Key words
Zr-4 alloy/surface nanocrystallization/mechanical properties/surface mechanical rolling treatment (SMRT)引用本文复制引用
基金项目
国家自然科学基金(51471129)
国家自然科学基金(51321003)
国家重点基础研究发展计划(“973”计划)(2014CB644003)
出版年
2017
NETL
NSTL
维普
万方数据