摘要
采用常压氢气烧结法制备了W-ZrC材料,分析了添加ZrC对材料室温和高温力学性能与组织的影响,并对高热负荷冲击下的损伤行为进行了研究。结果表明,添加ZrC有利于钨材料的致密化和晶粒细化,提高了烧结态钨材料的强韧性:其中W-3%ZrC(质量分数,下同)的相对密度和室温抗拉强度分别达到99.7%和472 MPa,400℃至1000℃的抗拉强度仍保持在420MPa左右,应变由室温的3.4%增加至1000℃时的11%。高热负荷冲击试验表明,高强度能提高材料抗高热负荷冲击能力,W-3%ZrC在200 MW/m^2 (5 ms)以下的高热负荷冲击表面基本无裂纹,在300～400 MW/m^2时出现的主裂纹网格间距明显较W-0.7%ZrC小。随高热负荷冲击能量增加,裂纹大致沿纵向向基体内部逐渐扩展。裂纹扩展遇到第二相粒子时,部分穿过第二相粒子,部分终止于第二相粒子。裂纹穿过第二相粒子时,裂纹与第二相粒子发生了交互作用,裂纹扩展方向发生改变。
W-ZrC materials were prepared by ordinary consolidation sintering. The effects of ZrC addition on the mechanical properties and microstructure of the materials at room temperature and high temperature were studied, and the damage behavior under high heat flux shock was investigated. The results show that ZrC is beneficial to densification and grain refinement, and improves the stren gth and toughness of W materials. The relative density and room temperature tensile strength of W-3 wt%ZrC can reach 99.7% and 472 MPa, respectively, and the tensile strength at 400~1000 oC is maintained at 420 MPa, but the strain increases from 3.4% at room te mperature to 11% at 1000 oC. The high heat flux shock shows that high strength can improve the impact resistance of materials against high heat loads. The surface of W-3 wt%ZrC material has few cracks under a high heat flux shock of 200 MW/m^2(5 ms). The main crack spacing of W-3 ZrC is smaller than that of W-0.7 wt%ZrC at 300~400 MW/m^2. With the increase of the high heat load energy, the cracks gradually expand along the longitudinal direction. Microstructure shows that ZrC can consume the crack propagation en ergy and hinder crack propagation.
作者
李鹏飞
范景莲
章曼
韩勇
孙志雨
吕永齐
田家敏
Li Pengfei;Fan Jinglian;Zhang Man;Han Yong;Sun Zhiyu;Lv Yongqi;Tian Jiamin(State Key Laboratory for Powder Metallurgy,Central South University,Changsha 410083,China)
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2019年第2期517-523,共7页
Rare Metal Materials and Engineering
基金
国家自然科学基金(51474242
51404308)
国家科技部重大专项(2014GB115000)
关键词
第二相粒子
高温强度
导热系数
高热负荷
裂纹扩展
second phase particle
high temperature strength
thermal conductivity
transient high-heat flux
crack propagation
