ISSN:
1662-9752
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:
Three different approaches for metal to ceramic brazing are compared using the example ofSi3N4/TiN-steel joints: the use of an active filler metal (single layer brazing system), themetallisation of the ceramic and brazing with a non active filler (two-layer brazing system), the useof a composite brazing filler system (three layer brazing system). Different aspects are analysed: thedevelopment of the joint’s microstructure in the as-brazed state, the thermally induced residualstresses and the resulting bend strength of the joint’s strength.With two layers and three layers brazing system, bend strength of about 400 MPa, about 15%higher then single filler metal, were achieved. The three layer brazing system has two advantages:firstly one step processing secondly lower scattering of joint bend strength compared to two layersbrazing system.The key factors in all cases are the selection of the brazing fillers and the braze design. In all cases acareful selection of the brazing fillers and the braze design are the key factors. The first criteria forthe selection of the brazing fillers for joints of dissimilar materials can be done by considering onlythe main filler characteristics like titanium content, processing temperature and yield stress. It’snecessary to simulate the joint behaviour by finite element simulation for verifying the finalselection of filler metals. It was clearly seen that the plasticity of the filler metal is the main factoraffecting residual stresses for the joint geometry in this current work
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/15/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.539-543.4008.pdf
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