真空硬銲氧化鋁/不鏽鋼接合機械性質與結構特性之研究

本研究觀察三種不同填料合金(BAg-8、CuSil-ABA填料及自製AgCuTi複合填料)對氧化鋁與SUS304硬銲接合特性的影響。實驗中採用氧化鋁陶瓷（≥95% Al2O3）進行實驗，並嘗試利用物理氣相沈積方式製備陶瓷表面金屬化層，再使用BAg-8填料進行硬銲。在活性硬銲方面，採用CuSil-ABA及自製AgCuTi複合填料，直接針對陶瓷進行真空活性硬銲實驗。硬銲結構分析結果顯示，氧化鋁與304不鏽鋼先用預金屬化法後用BAg-8填料在900℃下硬銲時，從陶瓷一側到不鏽鋼其主要介面的反應層依序為：Al2O3/TiO2/Cu3Ti3O+Ti3Ag/(Ag-Cu) / TiFe2+TiO /SS；活性硬銲所產生的主要介面反應層為：Al2O3/TiO /Cu3Ti3O+Ti3Ag/(Ag-Cu)+Ti/ TiFe2+TiO/ SS。若使用添加鎢顆粒之複合填料後，其生成介面層大致與CuSil-ABA相近，但其介面反應層在XRD下峰值強度較弱且利用SEM觀察後明顯較薄。且經EPMA分析，於填料中W顆粒周圍發現W會與Ti元素與O元素產生析出相，其厚度隨硬銲溫度越高而上升。硬度實驗結果顯示，預金屬化於850℃與活性硬銲於900℃時，其基材與填料合金硬度變化差異較小，相較於其它硬銲溫度而言，可避免應力集中現象發生。附著力測試結果顯示，最大接合強度乃使用BAg-8填料合金於850℃硬銲時持溫30分鐘，附著力值達到11.11 MPa；使用CuSil-ABA填料合金於900℃硬銲時持溫30分鐘其值亦有13.54 MPa；使用自製AgCuTi/W填料於900℃硬銲時持溫30分也可以達到13.2 MPa。本文並利用有限元素法對接合件進行殘留應力的分析。計算表面殘留應力的最大值，均分佈在A1203側之填料附近，這與實際硬銲中發現的陶瓷裂紋的位置是一致的。另外對複合銲料的殘留應力模擬結果指出，添加顆粒的填料其熱膨脹係數對殘留應力之影響並不明顯，本文中藉由外加的W顆粒降低活性填料的熱膨脹係數，進而減緩陶瓷/金屬硬銲接合件之殘留應力。模擬結果表明，降低填料/陶瓷兩者間的熱膨脹係數雖然無顯著降低硬銲接合件的殘留應力峰值，但其添加顆粒可以分散應力集中區域。顯示複合銲料亦可解決陶瓷/金屬接合件殘留應力過高的問題。

關鍵字

真空硬銲製程；活性銲料；殘留應力；介面反應

並列摘要

In this study, we compared three different kinds of filler metal’s effect (BAg-8、CuSil-ABA、AgCuTiW composite filler) on vacuum brazed Al2O3 and SUS304 stainless steel. During experimental procedual, first we used physical vapor deposition (PVD), we fabricated the metallization layer on the ceramic’s surface by sputtering, then brazed by using BAg-8 filler metals. For active filler metals brazing method, we used CuSil-ABA and AgCuTiW composite filler brazed non-metallized ceramic directly. Experiment results showed that the interfacial reactions were complex, including Al2O3/TiO2/ Cu3Ti3O+Ti3Ag/(Ag-Cu) /TiFe2+TiO/SS between Al2O3 and SS by using pre-metallization methods; by using active brazing methods, its major interfacial reaction layers included Al2O3/TiO /Cu3Ti3O+Ti3Ag/(Ag-Cu)+Ti /TiFe2+TiO/ SS. When using composite filler which added tungsten particles, its XRD patterns were not only similar to CuSil-ABA, but also its XRD peaks were lower. By checked by SEM, its reaction layers were thinner than CuSil-ABA. We also checked by EPMA analysis, it showed the Oxygen and titanium element could seperate phase around the tungsten particles, this phase’s thickness will increase when brazing temperature rise. And the micro-hardness test results showed that when brazing temperature are 850℃ and 900℃, the hardness difference between based material and filler metalsare smaller than other brazing conditions, and it can avoid stress-concentration efficiently. The pull-off test results were shown that the highest tensile strength was 11.11 MPa when brazed at 850℃ for 30 min by BAg-8 filler metals, for CuSil-ABA filler metals, its highest strength was about 13.54 MPa which brazed at 900℃ for 30 min, by used AgCuTiW composite filler, its highest strength was about 13.2 MPa which brazed at 900℃ for 30 min. This paper also has residual stress analysis for joining pieces by finite element method. The result has shown that the maximum residual stresses are distributed in the A1203 side near the filler, which is similar to the actual brazing ceramic crack position. In addition to the composite filler, residual stress simulation results indicated the CTE of the composite filler for the residual stress was important. Although there is no obvious decline on residual stress simulation, but added particle can disperse the Stress concentration area. This method might show the composited fillers also sloved the residual stress problem on ceramic/metal brazing.

並列關鍵字

vacuum brazing process ； active filler metal ； residual stress ； interface reaction

參考文獻

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真空硬銲氧化鋁/不鏽鋼接合機械性質與結構特性之研究

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