电子束选区熔化W?B合金的显微组织和力学性能
Microstructure and mechanical properties of W?B alloys prepared by selective electron beam melting
游亮 1王建 2杨广宇2
作者信息
- 1. 东北大学材料科学与工程学院,沈阳 110819;西北有色金属研究院金属多孔材料国家重点实验室,西安 710016
- 2. 西北有色金属研究院金属多孔材料国家重点实验室,西安 710016
- 折叠
摘要
针对电子束选区熔化纯钨晶粒粗大的问题,选取B作为晶粒细化元素,研究成形工艺参数对W‒B合金致密化、显微组织和力学性能的影响.结果发现,当电子束束流强度为 15 mA,扫描速度为 300 mm·s‒1,体能量密度为 1200 J·mm‒3 时,W‒B合金试样相对密度最高,孔洞及未熔合缺陷最少,微裂纹基本得到抑制.B元素引起的成分过冷有效细化了W晶粒尺寸,显微组织由粗大柱状晶转变为细小的柱状树枝晶,平均晶粒尺寸为 8.26 μm.W‒B合金的最高硬度达到HV 672,最高抗压强度达到1598 MPa,断裂机制为解理断裂.
Abstract
To solve the problem of grain coarseness in pure tungsten prepared by selective electron beam melting(SEBM),B was selected as the grain refinement element.The influence of forming process parameters on the densification,microstructure,and mechanical properties of the W‒B alloys was investigated.It is found that when the electron beam current intensity is 15 mA,the scanning speed is 300 mm·s‒1,and the volume energy density is 1200 J·mm‒3,the density of W‒B alloy samples is the highest,the pores and unfused powders are the least,and the microcracks are basically suppressed.The constitutional undercooling caused by element B effectively refines the grain size of W formed by SEBM,and the microstructure changes from coarse columnar crystal to fine columnar dendrites with an average size of～8.26 μm.The highest hardness of the W‒B alloys is HV 672,and the highest ultimate compressive strength is 1598 MPa.The fracture mechanism is mainly cleavage fracture.
关键词
电子束选区熔化/W-B合金/成分过冷/晶粒细化Key words
selective electron beam melting/W-B alloys/constitutional undercooling/grain refinement引用本文复制引用
出版年
2024
国家科技期刊平台
NSTL
万方数据