- 學位論文
高頻感應焊接應用於SMA連接器本體之製程參數與材質影響探討
Study on the Process Parameters of High Frequency Induction Welding and its Property Influences in the Brazing of SMA Connector Body
摘要
傳統以火焰加熱進行焊接時，因加熱時間長而造表面形成較多氧化層，阻絕熱的傳遞。火焰溫度約為1100 ℃至3300 ℃，已超過連接器本體黃銅材質之931℃熔點，所以無法直接對長寬高各為15×15×7(mm)之小元件進行局部加熱。感應加熱利用交變磁場，使元件表面產生渦電流，再由電能轉換成熱能，可控制小元件之局部受熱，以單環形外徑2 mm感應線圈，加熱區域可控制在5~8 mm範圍，使加熱效率提升。本文以SMA (Sub Miniature version A)連接器本體為焊接對象，使用銀合金填料金屬與助焊劑，以不同之加熱時間、功率參數與助焊劑配方進行焊接，量測與觀察焊接接合之情形，提出量測殘餘助焊劑之實驗方法，同時探討焊接前後本體之硬度與顯微組織變化。對於助焊劑於焊接過程會產生喷濺探討，是以不同廠牌助焊劑進行測試。對於感應加熱之溫度會產生晶粒結構變化，進行焊接前後之硬度試驗，觀察本體不同區域之組織變化。實驗是以高頻感應加熱機進行焊接，調整時間參數與加熱時間，對外徑5.3 mm空心圓柱表面加熱，約4.5~6.5秒可以完成本體焊接，加熱時間若為5.6秒與80%功率參數可得較佳焊道。
並列摘要
For conventional flame welding, the formation of thick oxidation layer on surface due to the extensive heating duration usually causes the deterioration in the thermal transfer of the process. Moreover, the flame can easily reaches 1100℃ to 3300℃ which is far higher than the melting point (931℃) of the brass used in the connector body. Especially for the small workpiece with dimensions of 15×15×7 mm, a local heating for the welding will be infeasible. On the other hand, with an induction heater of single coil and 2 mm in diameter, the heating zone can be easily controlled within 5 ~ 8 mm range. The alternating magnetic field supplied by the induction heater generates the eddy current on specimen surface and converts the electric energy into thermal energy. Since the induction magnetic field is confined near the coil, the effectiveness of local heating is obtained. In this study, an SMA (Sub Miniature version A) connector body was used to investigate the brazing process by employing silver alloy filler and flux. Brazing was performed under different heating time, flux formula and power rating, and the quality of the brazing joint was examined. The residues from the spray of flux were also recorded. Moreover, the variation in the microstructure and hardness in the heat affected zone was also examined. Depending on the power rating of the induction coil, the hollow cylinder with 5.3 mm diameter was able to be brazed within 4.5~6.5 s. However, it was found that with heating time of 5.6 s and 80% power rating, the brazing joint could reach the best quality. The splashing and the residual amount of flux near the brazing joint for different paste formula was also compared.