薄板Ti-6Al-4V銲件殘留應力與角變形分析

A study on the residual stress and angular distortion of thin plate Ti-6Al-4V alloy weldments

黃子育(Tzu-Yu Huang)

指導教授 ： 鄭慶民

國立臺灣師範大學/科技學院/機電科技研究所/碩士(2010年)

摘要

本研究主要針對鈦合金經過雷射銲接及TIG後銲接，探討其殘留應力及角變形之改變。實驗用的材料為Ti-6Al-4V鈦合金，材料厚度為1.2mm，銲接方式則採用Nd : YAG雷射銲接與惰性氣體鎢極電弧銲接（TIG），採取不添加任何填料的對接方式。銲接過後，再分別進行殘留應力量測及角變形量測。
　　針對Ti-6Al-4V鈦合金以TIG銲接，同樣以不填料銲接方式發現，相同電壓下，以60A之電流及17cm/min走速進行銲接時，輸入之熱量較50A電流及13cm/min走速之銲接低，但熔融率相同，銲道之品質相近，兩組參數以角變形量測後，電流大走速快的銲件角變形較小，但與雷射銲件同樣以不填料銲接方式相比，雷射銲件之銲道比TIG銲件小許多，角變形也小很多。
在殘留應力方面，TIG以60A之電流及17cm/min走速進行銲接後之殘留應力與50A電流及13cm/min走速之銲件相比，銲件之殘留應力分布區域相似，但50A電流及13cm/min走速之銲件殘留之拉應力較大，壓應力小，若與雷射銲件相比殘留應力分布區域相似，但雷射銲件之殘留應力均小於TIG銲件。

關鍵字

HASH(0x1ee2aac0) ； 鈦合金 ； 殘留應力 ； 角變形 ； Nd:YAG雷射銲接

並列摘要

This research used two different welding methods: TIG and Laser, to apply to Ti Alloy test pieces under the preset parameters to weld and to analyze the thermal stress and angular distortion. The material used for the test pieces was Ti Alloy (Ti-6A1-4V), which were 1.2 mm thick, and were adapted to butt joint to weld without using any fillets. The residual stress and angular distortion of the test pieces were then measured separately.
　　The test pieces welded by TIG at constant voltage were tested by using two criterions: one was at 60 amperes current under 17cm/min travel speed; the other was at 50 amperes current under 13 cm/min travel speed with relatively larger capacities. These two kinds of test pieces, which were welded by TIG, had nearly the same fusion rate and welding quality. However, the pieces tested with relatively stronger currents and higher travel speed (60 amperes and 17 cm/min) had smaller angular distortion. Compared with using the Laser welding method to weld without using fillets, the welding size and angular distortion of the test pieces were much smaller than using the TIG ones.
　　With regard to the residual stress, the results of using the TIG welding at the current of 60 amperes and the travel speed of 17 cm/min had roughly the same residual stress on hot zone as the welding at the current of 50 amperes and the travel speed of 13 cm/min. As with the aspect of tensile stress, the TIG welding at the current of 50 amperes and the travel speed of 13 cm/min had larger tensile stress and smaller compression stress. As compared with the Laser welding, TIG welding had similar residual stress distribution pattern in the test pieces. However, the residual stress in the Laser welding pieces was smaller than those in the TIG welding.

並列關鍵字

Ti-6Al-4V ； Ti Alloy ； Residual Stress ； Angular Distortion ； Nd: YAG ； TIG

參考文獻

7.The Japan carbon fiber manufactures association

18.S.W. Banovic, J.N. Dupont, and A.R. Marder, Dilution Control in Gas - Tungsten-Arc Welds Involving Super austenitic Stainless Steels and Nickel-Based Alloys, Metallurgical and Materials Transactions B, pp. 1171-1176, Vol. 32B, December 2001.

19. New Lessons in Arc Welding, The Lincoln Electric Company, p.8, 4th, 1992.

22. C.O. Brown and C.M. Banas, AWS Annual Mtg., San Francisco, April 1971.

23. G. A. Moraitis and G. N. Labeas, Residual Stress and Distortion Calculation of Laser Beam Welding for Aluminum Lap Joints, Journal of Materials Processing Technology, Vol. 198, pp. 260-269, 2008.