摘要硬质合金和钢之间的钎焊属于异种材质钎焊,由于硬质合金本身较脆,其热膨胀系数不足钢的一半,因此硬质合金和钢之间钎焊难度大,不易获得较高的钎焊接头强度,由此制约着硬质合金和钢焊接质量,影响生产应用。24515
本文以YG13硬质合金与S20钢作为钎焊试验材料,采用炉中钎焊,通过测量钎缝显微硬度、观察分析钎缝微观组织,测试钎焊接头组织成分以及测试力学性能等试验,研究钎料种类,钎焊材料表面处理方式和基体之间的受力状态等因素对研究硬质合金与低碳钢钎焊接头强度的影响。结果表明:工艺参数为银基钎料,表面由240#砂纸处理,受力状态最小的实验组合其钎焊强度最高,达到230.4Mpa;钎料种类对接头强度影响显著,银基钎料效果最好,粗糙度次之,受力状态影响最小;受力状态影响钎缝宽度,从而影响钎焊质量;实验设定的表面处理方式对钎缝组织形貌影响不大;钎缝不同位置的显微硬度不同。 毕业论文关键词:钎焊;硬质合金;工艺参数;钎焊强度
Abstract
Brazing between carbide and steel is a heterogeneous material brazing, carbide is brittle and its thermal expansion coefficient is less than half of the steel. So brazing between carbide and steel is difficult, also hard to obtain a high strength of brazed joints, which restricts the actual production and application.
The subject makes YG13 carbide alloy as the research object, welding to the matrix material of S20 by furnace brazing. In order to get a good brazed joint and high shear strength. A lot of welding methods are adopted, such as changing the surface cleaning of connector materials, choosing different fillers of brazing, adjusting different fixture pressure. The influence of brazing parameters on the microstructure and properties of brazed joints was analyzed by optical microscope (OM), digital micro-hardness tester and universal mechanical testing machine. According to the results, Solder significantly influence on joint strength, silver fillers is the best, different fixture pressure and surface cleaning of connector materials come second, other factors may affect the results; Stress of fixture affect the brazing quality affect by affecting the brazing seam width. Impact of surface treatment methods on micro-structure of brazing seam is little; Different locations of the brazing seam have disparate micro-hardness.
Keywords: brazing, carbide, process parameter, brazing strength
目录
1.绪论 1
1.1引言 1
1.2钎焊技术 1
1.2.1钎焊及其分类 1
1.2.2钎焊技术的优点 2
1.2.3钎焊技术的发展与应用 2
1.3硬质合金钎焊 3
1.3.1硬质合金及其分类 3
1.3.2硬质合金的性能 3
1.3.3硬质合金钎焊及其难点 4
1.3.4影响硬质合金钎焊强度的因素 5
1.3.5硬质合金钎焊目前进展 5
1.4钎料的分类与钎剂的选用 6
1.4.1银基钎料 6
1.4.2 铜基钎料 7
1.4.3钎剂的选用 7
1.5钎焊表面的润湿与铺展 7
1.5.1固体金属表面结构 7
1.5.2润湿的分类 8
1.5.3钎料的毛细填缝过程 8
1.5.4影响钎料润湿性的因素 9
1.6 钎焊质量检验与评价 10
1.6.1钎焊质量检验 10
1.6.2 钎焊质量的评价 11
2.实验部分 12
2.1实验材料 12
2.2实验设备 13
2.3实验方法 13