銀錫及銅錫焊料中鈦添加量對不鏽鋼及玻璃接合機構與機械性質影響

Abstract

本研究主要是利用自備金屬焊料Ag-Sn-Ti及Cu-Sn-Ti在750°C下持溫1小時接合304不鏽鋼及Pyrex玻璃，運用於太陽能熱水器真空集熱管。並對接合後的試片利用SEM(EDS)對介面微觀結構分析及利用剪應力與氦氣測漏儀分析其機械性質。 利用Ag-Sn-Ti接合後焊料內部皆以Ag3Sn及Sn(O)相為主，沒有添加Ti時，不鏽鋼側及玻璃兩側皆沒有反應層產生。添加Ti後則產生Ti6Sn5及Ti2Sn3的相，且與不鏽鋼中的Fe反應形成Fe2TiSn相；以及部分Sn固溶入不鏽鋼基材中形成FeSn2相。利用Cu-Sn-Ti接合後焊料內部已Cu6Sn5、Cu3Sn及Sn(O)相為主，沒有添加Ti時焊料與不鏽鋼及玻璃兩側皆沒有反應層產生。添加Ti後，焊料中Ti、Sn與Fe反應形成Fe2TiSn相，在不鏽鋼側介面處也形成Fe2TiSn反應層；此外Cu、Sn固溶入不鏽鋼內形成FeCu2Sn。 對試片剪應力分析，根據ISO_13124：201122的測試標準量測結果19Ag-76Sn-5Ti、18Ag-72Sn-10Ti、19Cu-76Sn-5Ti及18Cu-72Sn-10Ti接合之試片皆斷裂在玻璃側，其最大應力平均值分別為4.89MPa、4.31MPa、3.50MPa及2.60MPa。再利用氦氣測漏儀量測期氣密性後，Ag-Sn-Ti系統中可發現添加5%Ti的氣密性為1.1×10-4 mbar•1/s較添加10%Ti的氣密性1.2×10-8 mbar•1/s來的差，可判斷出Ag-Sn-Ti系統中Fe2TiSn相的量對接合效果之影響。Cu-Sn-Ti系統中添加5%Ti的氣密性為4.6×10-5mbar•1/s 較添加10%Ti的氣密性3.3×10-7mbar•1/s 來的差。可判斷出在Cu-Sn-Ti系統中Fe2TiSn相的量及反應層厚度增加可使氣密性效果更為良好。

Joining of 304 Stainless Steel with Pyrex Glass using Ag–Sn and Cu–Sn fillers was fabricated at 750°C for 1 hr. The microstructure of the joints were characterized using scanning electron microscopy (SEM). In addition, universal testing machine and Helium leakage tests were used to analyze the mechanical properties of the soldering specimens. With no Ti addition into the Ag–Sn filler, the joint contained Ag3Sn and Sn(O) was observed between 304 Stainless steel and Pyrex glass. With adding 5%Ti and 10%Ti, respectiveily into the Ag–Sn filler, the joint comprised of Ag3Sn, Sn(O), Ti6Sn5, Ti2Sn3 and Fe2TiSn, indicating that Fe would diffuse into the Ag-Sn-Ti filler. The FeSn2 phase was also observed in the 304 Stainless steel. It was believed that the affinity of Fe-Sn was stronger than that of Fe-Ti. With no Ti addition into the Cu–Sn filler, the primary joint contained Cu6Sn5, Cu3Sn and Sn(O) phases was observed between 304 Stainless steel and Pyrex glass. With adding 5%Ti and 10% Ti into the Cu–Sn filler, the morphology of Fe2TiSn could be a layer or globular, respectiveily, nearby the 304 stainless steel. Besides, the joint comprised of Cu6Sn5, Fe2TiSn and Sn(O) phases. A two-phase FeCu2Sn+ (Fe,Cr) was also found beyond the Fe2TiSn layer. Duing the test of bonding strength, all specimens were broken in the Pyrex glass, indicating that the bonding between substrates were excellent. In Helium leakage tests, the steel/18Ag-72Sn-10Ti/glass joint (1.2×10-8 mbar•1/s) was better than the steel/19Ag-76Sn-5Ti/glass joint (1.1×10-4 mbar•1/s) because the amount of Fe2TiSn phase is increased in Ag-Sn-Ti filler. Additionally, it was also found that 10% Ti additive in the Cu-Sn-Ti filler presented a lower leaking rate (3.3×10-7mbar•1/s).