| 镍基单晶高温合金钎焊接头的微观组织与性能 |
| |
| 引用本文： | 孙元,赵旭,苏瑾,侯星宇,王诗洋,丁雨田.镍基单晶高温合金钎焊接头的微观组织与性能[J].焊接学报,2020,41(7):32-38. |
| |
| 作者姓名： | 孙元 赵旭 苏瑾 侯星宇 王诗洋 丁雨田 |
| |
| 作者单位： | 1.中国科学院金属研究所，沈阳， 110016 |
| |
| 基金项目： | 航空动力基金;国家自然科学基金 |
| |
| 摘 要： | 采用一种含B，Si的镍基合金钎料钎焊CMSX-4单晶高温合金，利用SEM，EPMA分析接头的微观组织与相组成，探究降熔元素B和Si的扩散机制及接头形成机理. 结果表明，不同间隙焊缝的微观组织相似，相组成相同，但随着间隙的增加，焊缝中的硼化物析出相增多，同时出现微孔等缺陷；对于相同焊缝间隙的接头，随着保温时间的延长，焊缝中的硼化物相的平均尺寸在一定程度上增大，且分布更加集中，母材与焊缝间的界面连接层厚度增加. 钎焊过程中，B元素集中分布于焊缝中心区，与Cr，W，Mo等元素反应，形成脆性硼化物相M3B2，B元素未向母材中扩散，近焊缝区中未见硼化物相析出；Si元素不仅在焊缝中心区形成镍硅化物相，也向母材中扩散，在近焊缝区形成含Si元素的镍基固溶体. 对不同焊缝间隙与保温时间的单晶钎焊接头在980 ℃/100 MPa条件下进行持久性能测试. 结果表明，单晶钎焊接头的持久寿命随着焊缝间隙的增加而降低，随保温时间的延长而升高，但当保温时间延长至30 min以上时，接头持久寿命没有显著增加.
|
| 关 键 词： | 单晶高温合金 钎焊间隙 保温时间 持久寿命 |
| 收稿时间： | 2020-04-10 |
Microstructure and properties of nickel-based single crystal superalloy brazed joints |
| |
| Affiliation: | 1.Institute of Metal Research, Chinese Academy of Science, Shenyang, 110016, China2.State Key Laboratory of Advanced and Recycling of Nonferrous Metals, Lanzhou University of Technology, Lanzhou, 730050, China3.AECC Xi’an Aero-Engine LTD., Xi’an, 710021, China |
| |
| Abstract: | The CMSX-4 single crystal superalloy was brazed by a Ni-based braze alloy containing melting point depressant elements B and Si, and the microstructure and element distribution of the joint were analyzed by SEM and EPMA. The diffusion mechanism of the melting point depressant elements B and Si and the forming mechanism of joint were investigated. The results indicated the joints with different brazing gap demonstrated similar microstructure and phase composition. However, as the width of the brazing gap increased, the precipitation of boride in the seam increased, while defects such as pores began to appear simultaneously. As the holding time increased, the average size of boride slightly increased and its distribution is more concentrated, and the thickness of the interface bonding zone between the base material and the brazing seam increased. During the brazing process, B mainly concentrated on the central of the seam and reacted with elements such as Co, W, Mo, etc. to form a brittle boride phase M3B2. Note that no brittle phase precipitated in the near-seam base metal. It can be inferred that B does not diffuse into the base metal. The Si element not only formed a silicide phase in the central of the seam but also diffused into the matrix material, thereby forming a Si-containing solid solution phase in the near the brazing seam. The stress rupture properties of joints with different gap and holding time were tested at 980 °C/100 MPa. It was found that the stress rupture life of the joint decreased with the increase of the weld gap, and increased with the extension of the holding time. When the holding time further prolonged, the stress rupture life was not significantly increased. |
| |
| Keywords: | |
| 本文献已被 万方数据 等数据库收录！ |
| 点击此处可从《焊接学报》浏览原始摘要信息 |
|
点击此处可从《焊接学报》下载全文 |
|
