钼与石墨钎焊工艺参数及组织分析
毕业论文关键词：石墨；钼；真空钎焊；Ag-Cu-Ti活性钎料；钎焊温度；保温时间
Abstract With the rapid development of aerospace science and technology and other fields ofscience, the use of welded structure of molybdenum and graphite increases. This articledescribes the chemical and physical properties of molybdenum and graphite as well asgraphite and molybdenum research status brazing.Because graphite is relatively poor wetting, solder most difficult to effectively wetgraphite, so this issue with an active solder Ag-Cu-Ti molybdenum and graphite vacuumbrazing. A scanning electron microscope (SEM) and its spectroscopy (EDS) and othermethods, the microstructure of brazed joints were observed and analyzed, studied underdifferent soldering processes (mainly for soldering temperature and time), the jointelements diffusion and distribution.Experimental results show that: when the brazing temperature reaches 830 ℃ or moreand holding more than 3 minutes, Ag-Cu-Ti brazing material that is liquefied, Ag-Cueutectic reaction. With the increase of brazing temperature and holding time, Ag-Cu-Tibrazing material can occur more fully diffused and graphite and molybdenum substrate C,Mo elements have begun to varying degrees of diffusion. Brazing alloy Ti elements undercertain process parameters, will work with graphite element C reacts generate TiC layer,effectively improve the wettability, interfacial tension to improve graphite; under certainprocess parameters, brazing alloy the Ti elements are molybdenum substrate in an infinitesolid solution Mo element, provided the conditions for the vacuum brazing. The resultsobtained in the case of existing laboratory equipment and data, using Ag72-Cu28-Ti3active brazing of high-strength graphite and pure molybdenum brazing optimum processparameters.
Keywords：graphite; molybdenum; vacuum brazing; Ag-Cu-Ti active brazing;brazing temperature; holding time
目 录
第一章 绪论.. 1
1.1引言.1
1.2钎焊技术的特点.2
1.2.1 钎焊技术的优缺点..2
1.2.2 钎焊工艺 2
1.2.3 真空炉中钎焊的优缺点..3
1.2.4 钎焊过程 4
1.2.5 钎料5
1.3钼及其合金的钎焊研究现状.7
1.4石墨材料的钎焊性9
1.5本课题主要的研究内容. 10
第二章 实验方法及设备.12
2.1实验材料.. 12
2.2实验设备.. 13
2.3实验过程.. 14
2.4钎焊工艺参数的选择.. 14
2.4.1 钎焊温度. 14
2.4.2 保温时间 15
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