Corrosion behaviors of Al-Si-Cu-based filler metals and 6061-T6 brazements

The corrosion behaviors of a series of Al-Si-Cu-based filler metals and the 6061-T6 butt joints brazed with these filler metals are evaluated by polarization tests and immersion tests in a 3.5% NaCl aqueous solution. For comparison, a traditional Al-12Si filler metal is also employed. The results indicate that the Al-Si-Cu-based filler metals before brazing possess much higher corrosion current densities and pitting tendencies than the Al-12Si filler metal. However, brazing of the 6061-T6 alloy with an Al-12Si filler metal produces a wider butt joint, which, in this case, creates a more extensive corrosion region. Severe galvanic corrosion occurs at the 6061-T6 joints when brazed with Al-Si-Cu-based filler metals. However, in the case of the 6061-T6/Al-12Si brazements, selective corrosion of the Al-12Si eutectic phase can be observed. The bonding strengths of the 6061-T6 butt joints brazed with various filler metals are also measured before and after the immersion tests.     

Welding of SiC particle reinforced 6061 Al matrix composite with pulsed TIG

1　INTRODUCTIONDiscontinuously(particle,whiskerandshortfiber)reinforcedaluminumalloycompositeshavebecomeanattractivestructuralmaterialformanyindustrialfieldsowingtoitsexcellentproperties(e.g.highspecificstrength,highspecificstiffnessandgoodwearresistance)…     

A preliminary study on filler metals for vacuum brazing of Al/Ti

In this paper,nine new filler metals contained Sn and Ga based on Al-11.5Si have been designed for vacuum brazing of Al/Ti.It is found that the addition of Sn and Ga can lower the solidus of filler metal,change the structure of intermetallic compound formed in the joint during brazing,and enhance the strength of joint.But the detail mechanism need further research.     

活性填料控制的先驱体裂解陶瓷的尺寸变化

对单一先驱体、先驱体／惰性填料、先驱体／活性填料体系裂解陶瓷的尺寸变化进行了模型分析。从理论上分析了活性填料体积分数与裂解陶瓷体积收缩率和线收缩率之间的关系，揭示了活性填料的临界体积分数与活性填料反应的产率、反应前后的密度比之间的相关性，以聚碳硅烷先驱体为例，预测了在不同反应情况下，常见活性填料的临界体积分数，增加活性填料体积分数，可降低陶瓷产物的体积收缩率和气孔率。     

金刚石锯片焊接技术的研究

本文简要回顾了金刚石锯片焊接的发展历程，较详尽的综述了目前流行的向种焊接方法，并对各种焊接方法的特点进行了评价。主要讨论了钎焊技术的应用特点，研究了钎焊工艺过程对焊接结果的影响，指出了钎焊温度、保温时间与接头抗剪强度的关系，简要阐述了一系列专用钎料的性能以及选择要点。本文认为进一步改进金刚石锯片接用钎料是满足目前工业生产的主要手段，加强激光焊接技术的研究是实现金刚石锯片焊接强度跨越式发展的重要措施。     

裂纹修复与激光技术

综述了裂纹修复原理和常规修复方法 ,着重阐述了激光填料焊和激光熔覆技术在裂纹修复中的应用现状 ,就目前裂纹修复中存在的问题及其发展方向提出了看法     

储液器多工位自动火焰钎焊机

研究开发了转盘式多工位自动火焰钎焊机，适用于压缩机储液器的大批量钎焊生产。通过更换不同的夹具，亦可用于不同种类工件的钎焊。该钎焊机采用PLC控制，配有气体流量／压力闭环返馈控制系统及人机界面系统，可方便地设置和修改工艺参数，火焰强度稳定，钎焊质量优良。     

空调四通转换阀体的感应钎焊

介绍了感应加热电源在铜与不锈钢钎焊方面的应用，并结合具体产品提出了适合产品钎焊的感电源类型和具体的工艺参数组合。     

Influence of the magnetic field on the alignment degree of the anisotropic strontium ferrites for elastomer bonded magnets

In this work, the influence of the magnetic field on the alignment degree of the magnetic particles and on the magnetic energy flux of elastomer bonded magnets are investigated. For the investigations, a strontium ferrite filled nitrile butadiene rubber is used. The change of magnetic flux density in the injection molding tool cavity was realized by changing the current at the rectifier. The alignment degree of the magnetic particles increases with increasing magnetic field in the injection molding tool cavity. Above a certain current strength, a saturation behavior of the alignment degree of the magnetic particles and the magnetic energy flux is reached. The change of the cavity magnetic field leads to an improvement of the pole angle error up to a current of 10 A. An increase of the current above 10 A leads to hardly any improvement of the pole angle error, since a saturation in the alignment of the magnetic particles has already been reached.     

环氧树脂在异型石材磨具中的应用

利用酚醛树脂作为结合剂、环氧树脂作为改良剂制备异型石材磨具,研究环氧树脂、酚醛树脂和致孔填充剂含量对细磨磨具的磨削性能和抛光磨具的抛光性能的影响。要得到较高的磨削比和抛光光泽度,各组分的最佳含量（质量分数）值是：酚醛树脂为２５％～２０％,环氧树脂为２０％～２５％,致孔填充剂为２０％～２５％。