ISSN:
1013-9826
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
High purity alumina/stainless steel joints were produced via activated molybdenummanganese(Mo-Mn) route using 72Ag-28Cu solder. Microstructures of the metallized ceramic andjoint sections were observed by scanning electron microscopy. Joint strength was tested byshear-loading method. Some process factors were characterized and analyzed, which includetemperature, holding time and heating and cooling rate in ceramic metallization process. The effectsof Ni plating and succedent annealing were also investigated. Experimental results show that,migration of glassy phases is the main mechanism of the ceramic metallization. Glass migrationdirection is from metallizing layer to ceramic side. In the ranges of temperature and holding time ofmetallization, joint strength firstly increases and then falls with temperature raising and timeextending. More fully sintered metallizing layer can be obtained while the temperature increasesfrom 1200oC to 1500oC, and the time prolongs from 30min to 60min. Over-sintering of themetallizing layer will take place with metallizing temperature of 1600 oC and overlong holding timeof 70min, which reduces the joint strength. The slower heating and cooling rate, and the annealingafter Ni plating both help enhance the seal strength, due to relieving or eliminating interlayerresidual thermal stress. However, too slow heating and cooling rate, such as 5 oC /min, is equivalentto overlong holding time and finally also decline the strength. A thin Ni coating helps solder wetmetallizing surface, and stops solder erode metallizing layer
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/55/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.353-358.2049.pdf
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