Szusta Jaroslaw, Tüzün Nail, Karakaş Özler
Faculty of Mechanical Engineering, Bialystok University of Technology, 45C Wiejska Str., 15-351 Bialystok, Poland.
Department of Mechanical Engineering, Faculty of Engineering, Pamukkale University, Kinikli, 20160 Denizli, Turkey.
Materials (Basel). 2020 Nov 13;13(22):5128. doi: 10.3390/ma13225128.
The current study investigates the load controlled fatigue properties of the microplasma arc welded thin titanium Grade 5 (6Al-4V) sheets. In order to explore the effect of weld geometry on the fatigue, two different welded joints were used in the experimental studies. Load controlled fatigue test results were evaluated to present an outlook on the behaviour of microplasma welded titanium alloy Grade 5 sheets under cyclic loading. Even though the previously published monotonic tests showed successful use of microplasma arc welding to join thin titanium Grade 5 sheets with mechanical properties comparable to the base metal, fatigue life of the welded joints was lower than the lives of samples without welds. In particular, the fatigue performance of overlap joints was very poor. This was presumed to be due to the changed material properties of the heat affected zone which was formed by the excess heat of the welding process as fractures often occurred at such locations. Based on experimental findings and fractographic observations, a clear adverse effect of welding process in material behaviour was discovered. Despite the concentrated heat of microplasma arc welding, post-weld heat treatment of the weld area is recommended to improve the mechanical behaviour of the welded joints.
当前的研究调查了微等离子弧焊5级薄钛板（6Al-4V）的载荷控制疲劳性能。为了探究焊接几何形状对疲劳的影响，在实验研究中使用了两种不同的焊接接头。对载荷控制疲劳试验结果进行了评估，以展现5级微等离子弧焊钛合金薄板在循环载荷下的行为。尽管先前发表的单调试验表明微等离子弧焊成功用于连接薄5级钛板，且焊接后的机械性能与母材相当，但焊接接头的疲劳寿命低于无焊接样品的寿命。特别是，搭接接头的疲劳性能非常差。据推测，这是由于焊接过程中产生的过多热量形成了热影响区，导致材料性能发生变化，因为断裂经常发生在这些位置。基于实验结果和断口观察，发现了焊接过程对材料行为有明显的不利影响。尽管微等离子弧焊热量集中，但建议对焊接区域进行焊后热处理，以改善焊接接头的机械性能。
