Joining of Si_3N_4-Si_3N_4 using CuNiTi alloy brazing filler

01lltrodnotionOwingtoitssuperiormechanicalproperties,thesiliconnitrideceramicisbecomingoneofthemostpotentialstructurematerialsinengineeringapplications.Insomecases,theSt3N4ceramicusuallyneedstobejoinedwithitselformetals.Recently,theAgCuTibrazingfillerInetalshavebeentvidelyusedl'-,I,buttheycontainratherhighquantityofAgupto57%Whichisanexpensivekindofmetal.Therefore.itisnecessarytodevelopanewkindofbracingfillerInetalsx\'ithsimil:ll'propertiestothatofAgCuTibrazingalloysbutwithoutsilver.Thewe…

Joining of Si_3N_4-Si_3N_4 using CuNiTi alloy brazing filler

Using newly developed Cu_(58)Ni_(12)Ti_(30) alloy as brazing filler metal. this paper has carried out the joining experiments of Si_3N_4-Si_3N_4 and the joint shear strength tests at room temperature. The joint brazed at 1.293K for 10 min exhibited the maximum strength value of 1572 MPa. The microstructures of the joint cross-section were observed and the elements area distributions on the interface were examined by means of scanning electron microscope with .X-ray wave-dispersion spectrometer. The phases formed in the joint were determined by X-ray diffraction analysis method The results showed that during the brazing process the active element Ti diffused to the interfaces and reacted with Si_3N_4, resulted in forming the reaction products TiN, NiTiSi, and Ti_5Si_3 (or TiSi) on the interfaces. Some effects on the trend to produce these compounds were attempted to explain from a thermodynamic point of view.