金基填料對碳化矽陶瓷與金屬接合之研究

Abstract

本研究以Au-18Ni、Au-3Ni-0.6Ti以及Au-0.75Ni-1.75V等三種金基合金銲料在真空硬銲爐中對熱壓燒結之SiC-U陶瓷、化學氣相沉積之CVD-SiC陶瓷、及KOVAR合金進行同種及異種接合實驗，然後利用三點抗彎試驗以測試抗彎強度並使用SEM及EDS分析陶瓷及Kovar合金之接合界面反應。 研究結果顯示使用熱壓燒結的SiC陶瓷進行接合時，由於陶瓷結構鬆散且顆粒尺寸差異大，接合過程中，銲料的成份元素會向陶瓷顆粒間隙滲透。在異種接合時，銲道會產生Si-Ni-Fe化合物，導致「凝固熱裂」現象而使接合件破裂。此「凝固熱裂」現象可以先藉由物理氣相沉積技術於熱壓燒結SiC-U陶瓷表面沉積Ti層後再施以異種接合，而獲得明顯改善，且得到良好的接合強度。 此外，使用化學氣相沉積SiC陶瓷進行接合時，三種金基銲料均可順利接合，其中以使用Au-3Ni-0.6Ti合金銲料進行異種接合可獲得最佳之接合抗彎強度。

The aim of this study was to join different silicon carbide (reaction-bonded-SiC/CVD-SiC) and KOVAR in using vacuum brazing process. Three types of Au-base filler metals including of Au-18Ni, Au-3Ni-0.6Ti and Au-0.75Ni-1.75V were used . Optical metallography and SEM/EDS analysis were used to investigate the reaction interface and also three-point-bend test was conducted to determine the bending strength. The experimental results show that the potential solidification cracking can be occurred in the interface between reaction-bonded silicon carbide and KOVAR. Several alloying elements of filler metals can diffuse into grain boundaries of silicon carbide and Si-Ni-Fe componds were formed. This phenomenon can be overcome successfully with the adding of PVD titanium layer and higher joining strength can be obtained. Besides, all three types of Au-base filler metals can give good joining of CVD-SiC and KOVAR. The filler metal Au-3Ni-0.6Ti has better performance with the highest bending strength.