程金保Cheng, Chin-Pao張文瀚Chang, Wen-Han2022-06-082021-10-252022-06-082021https://etds.lib.ntnu.edu.tw/thesis/detail/fe798508ab3b04fae1f19852bf9b775c/http://rportal.lib.ntnu.edu.tw/handle/20.500.12235/117549本研究使用摩擦攪拌銲接技術以對接的方式進行 Gr. 2 商業用純鈦的接 合，攪拌棒使用碳化鎢製成，攪拌棒傾斜角 3°、下壓深度 1.6 mm，探討使 用不同轉速、進給速度、攪拌棒凸銷形狀對於銲道機械性質影響。另外也探 討使用摩擦攪拌銲接與惰氣鎢極電弧銲接銲後試片在 3.5 wt %氯化鈉水溶液 中的抗腐蝕性比較。首先將接合之試片進行表面與斷面觀察、金相組織觀察、 微硬度試驗、拉伸試驗等來分析銲件的機械性質，最後進行電化學腐蝕試驗 來分析試片的抗腐蝕性。實驗結果顯示使用加大錐形凸銷攪拌棒、轉速 400 rpm、進給速度 50 mm/min 時可以得到較佳的銲接性質，抗拉強度可達 310.63 MPa，為母材的 92.25 %。在攪拌棒凸銷的形狀上，使用圓柱形凸銷攪拌棒可以形成較大的 攪拌區，但容易在材料內部產生缺陷;使用圓錐形凸銷攪拌棒則可以擴大成 功銲接的範圍，但因攪拌區較小造成銲接強度不足。除此之外，純鈦經過摩 擦攪拌銲接後在攪拌區內都可以觀察到明顯晶粒細化的效果，也讓該區域的 硬度有所提升，可達到 175 HV 左右。熱影響區的晶粒尺寸則變化不大，但 經過銲接後該區域硬度則有些微降低。在抗腐蝕性方面，經過摩擦攪拌銲接 的試片在攪拌區內由於晶粒細化的作用，其抗腐蝕性都有明顯的提升，該區 域內的抗腐蝕性不僅優於母材，也優於使用惰氣鎢極電弧銲接方法接合之試 片。In this study, friction stir welding was used to join Gr. 2 commercial pure titanium by means of butt joint. The stirring rod was made of tungsten carbide. The tilt angle of the stirring rod was 3° and the depression depth was 1.6 mm. The purpose of this study was to discuss the influence of using different rotation speeds, feed speeds, and the shapes of the pin of the stirring rod on the mechanical properties of the weld bead. In addition, the difference of corrosion resistance shown after friction stir welding and gas tungsten arc welding were in 3.5 wt % sodium chloride aqueous was also discussed. The experiment conducted surface and cross-section observation, tensile test, metallographic observation, microhardness test to analyze the mechanical properties, and finally ran an electrochemical corrosion resistance test to analyze the corrosion resistance.Experimental results showed that the best welding properties could be obtained when using enlarged conical stirring rod pin, the speed was 400 rpm and the feed speed was 50 mm/min. The tensile strength could reach 310.63 MPa, which was 92.25 % of the base material. Regarding the shape of the pin of the stirring rod, the use of cylindrical pin stirring rod could form a larger stir zone, but it was likely to produce inner cavity defects. Furthermore, the use of conical pin stirring rod could expand the range of successful welding, however, the smaller stir zone caused insufficient welding strength. Besides, after pure titanium was in the process of friction stir welding, significant effect of grainrefinement could be observed in the stir zone, and the hardness of this area had also been promoted to about 175 HV. The grain size of the heat-affected zone had not been greatly changed, but the hardness of the area slightly decreased after welding. In terms of corrosion resistance, due to the grain refinement of the friction stir welding test piece in the stir zone, its corrosion resistance had been significantly improved. The corrosion resistance in this area was not only better than the base material did, but also better than that of the specimen piece joined by gas tungsten arc welding process.摩擦攪拌銲接純鈦攪拌棒凸銷形狀微觀組織機械性質抗腐蝕性Friction stir weldingPure titaniumStirring rod pin shapeMicrostructureMechanical propertyCorrosion resistance學術論文