The study of infrared brazing Ti-6Al-4V and 17-4 PH using the BAg-8 filler
Date Issued
2004
Date
2004
Author(s)
Wang, Cheng-Yu
DOI
zh-TW
Abstract
本研究以紅外線加熱法，使用50μm厚之Ag基填料BAg-8來硬銲接合Ti-6Al-4V鈦合金及17-4 PH不鏽鋼(S.S.)。硬銲接合前分別對Ti-6Al-4V及17-4 PH進行表面處理，以鍍膜作為擴散阻隔層，期能阻擋填料與基材形成硬脆的介金屬相，以得到最佳剪力強度之條件。實驗結果顯示，在17-4 PH S.S.表面鍍鎳與鉻膜，可得到的最佳接合剪力強度約為117 MPa；而在Ti-6Al-4V表面鍍鉻膜，可得到的最佳接合剪強度約為120 MPa。由破斷途徑之分析可得知，在17-4 PH不鏽鋼進行表面處理，破斷面主要為Ti2Cu介金屬相。而在Ti-6Al-4V進行表面處理，破斷面主要為Ti2Cu介金屬相或少數為(Ti, Cu, Fe)三元合金相。在擴散阻隔層較厚時，因擴散阻隔層的阻擋效果較強，未能形成硬脆的Ti-Cu介金屬化合物，因此破斷都發生於鍍膜與被鍍基材界面之間；若是擴散阻隔層較薄時，因生成較厚的Ti-Cu硬脆介金屬相，此時破斷則發生於Ti-Cu介金屬化合物與基材界面之間。
Two kinds of dissimilar metals, Ti-6Al-4V and 17-4 PH stainless steel (S.S.), are joined by infrared vacuum brazing using BAg-8 filler metals with 50μm thickness. Before brazing, diffusion barrier coatings on Ti-6Al-4V or 17-4 PH S.S. are introduced. The aim of diffusion barriers is to prevent interdiffusion between two dissimilar metals from forming intermetallic compounds, and thus to get better shear strength. Experimental results show that Ni and Cr films coated on 17-4 PH S.S. can obtain the shear strength of 117 MPa, and Cr film coated on Ti-6Al-4V can obtain the shear strength of 120 MPa. By the SEM analysis of crack propagation, for surface coatings on 17-4 PH S.S., the specimens are fractured at the Ti2Cu intermetallic compound; and for surface coatings on Ti-6Al-4V, the specimens are fractured mostly at the Ti2Cu but few at the (Ti, Cu Fe) ternary alloy phases. As diffusion barriers are thick, the hard and brittle Ti-Cu intermetallic is not formed because the effect of diffusion barriers is significant. In this case, the crack takes place in between coating film and substrate. As diffusion barriers are thin, the hard and brittle Ti-Cu intermetallic is formed. Thus the crack takes place in between this brittle Ti-Cu intermetallic and the substrate.
Subjects
Ti-6Al-4V/17-4PH不鏽鋼接合
Ni,Cr擴散阻隔層
銀基填料
紅外線硬銲接合
界面顯微組織
接合剪強度
Ti-6Al-4V/17-4 PH S.S.
Ag-based filler metals
Ni, Cr diffusion barrier
Microstructures
Infrared brazing
Bonding strength
Type
thesis
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