摘要
航天级铝合金热管对装配连接提出了大功率高热流密度散热要求,传统胶接方式存在使用寿命短,可靠性差等缺点难以满足要求,针对铝合金热管进行了低温装配金属键连接试验研究。采用新型中间层材料成功的实现了6061铝合金的低温扩散钎焊。通过扫描电镜(SEM)和能谱分析(EDS)对接头微观组织和成分进行分析。结果表明,中间层镓和铜通过相互扩散形成了新相CuGa2;对保温温度为80℃、扩散时间分别为5 h/10 h/20 h的接头组织进行观察,发现扩散时间越长,镓和铜相互扩散越充分,中间层中残留的铜和镓越少,形成的接头组织越均匀致密;对界面传热系数和耐温性能进行了测试,结果表明金属键连接有很高的传热系数达到82362 W·(m2·K)-1,充分满足航天级热管大功率高热流密度散热要求;接头的耐温温度达到300℃,在300℃时,接头没有出现任何液化和重熔现象;最后通过对铝合金低温扩散钎焊过程的分析探讨了其中间层的扩散机制。
Aerospace-grade aluminum heat pipe had a high requirement of superpower and high heat flux removal in assembly bond- ing. Traditional cementing method was difficult to meet the requirements because of short service lifetime and poor reliability. A con- nection method of metallic bonding at low temperature used for aluminum alloy heat pipe was studied. The 6061 aluminum was success- fully bonded with a new kind of intermediary material. The microstructure and composition of the joints was analyzed by scanning elec- tron microscopy （SEM） and energy dispersive spectroscopy （EDS）. The results showed that a new phase CuGa2 was formed during the diffusion of the intermediary material Ga and Cu. The joints which were preserved under the temperature of 80 ℃ and diffused for 5 h/ 10 11/20 h each were observed. It was found that with more diffusion time, Ga and Cu diffused more adequately, Ga and Cu remained in the middle layer were less, and the joint structure formed was more uniform and compact. The coefficient of interface heat transfer was tested and the results suggested that the metallic bonding had a high coefficient which was about 82362 W. （m2 .K） -1 and fully met the requirements of aerospace grade heat pipe＇s high-power and high heat flux removal. The heat resistance performance of the joint was also tested and the results indicated that the melting point of the joint mierostrueture was higher than 300 ℃ and the joints showed no liquefaction and remehing phenomenon at the temperature of 300 ℃. Finally, through the analysis of the aluminum alloy low-temperature diffusion brazing process, the interlayer of the joints diffusion mechanism was discussed.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2013年第6期851-856,共6页
Chinese Journal of Rare Metals
基金
国家自然科学基金项目(51418050311HK0118)资助
关键词
热管
低温扩散钎焊
中间层
heat pipe
low-temperature diffusion brazing
interlayer
