The effect of friction stir welding parameters on microstructure and fatigue strength of CuZn37 brass alloys

Abstract

In this study, CuZn37 plates were joined by using friction stir welding. Welding was performed at a rotational speed of 750 rpm and a welding speed of 20 mm min −1 , and at a rotational speed of 1000 rpm and welding speeds of 20, 40, 60 mm min −1. The welded samples were analyzed at the macro-microstructural level. Moreover, both hardness and fatigue tests were performed on samples. At the end of the macrostructural examination of the samples welded at the rotational speed of 1000 rpm and the welding speed of 20 mm min −1 , the formation of tunnel defects was observed. While the best fatigue life results at low strain rates were obtained in the samples joined at the rotational speed of 750 rpm and the welding speed of 20 mm min −1 , those at high strain rates were obtained in the samples joined at the rotational speed of 1000 rpm and the welding speed of 60 mm min −1 .

Effects of Tool Rotation Speed and Pin Geometry on Properties in Friction Stir Welding of Brass

“…Figure 4 shows the acquired temperature measurements in the SZ via the thermocouples in FSW using a PA type stirrer pin. The peak temperature increased with increasing TRS due to the frictional heat input in accordance with previous studies [8,20,23,39,42,45], and it reached to 804 C for TRS of 1100 rpm. On the other hand, there is no significant change in the increment of the peak temperature with increasing of TRS from 800 to 1100 rpm, as can be seen from the graphs in Figure 4.…”

“…On the other hand, Cam et al [39] was not declared occurrence of TMAZ in the observations about FSW of CuZn37. There is a difference of opinion between this study and previous studies [8,44] on the determine TMAZ because, as well known, TMAZ is characterized by elongated and/or rotated grains between HAZ and SZ due to the forging action of tool [31,34]. It is thought that TMAZ has not clear both in this study and previous studies.…”

“…According to researchers, more flowing material and frictional heat was generated with increasing contact area of pin and also tensile properties of joint were positively influenced by them. Ozer et al [8] examined effects of TRS and WS on the microstructural properties, hardness, and fatigue strength of friction stir welded CuZn37 joints. They concluded that using a higher TRS at constant WS value resulted in high heat, and severe deformations, these led to growing grains in stir zone (SZ), thermo-mechanical affected zone (TMAZ), wide welding zone, low hardness, low fatigue life and formation of tunnel defect.…”

“…Therefore, friction stir welding (FSW) can be alternatively applied to joining of brass to overcome such problems associated with cycling of melting and solidification during fusion welds [3][4][5]. FSW is one of the solid-state joint methods and has unique advantages include requirement of minimum work-piece preparations, no requirement of additional metal and shielding gas, easy of handling, high levels of repeatability of weld parameters, no or low distortion, relatively low heat input and high weld performance [6][7][8]. FSW has mainly used to welding of aluminum (Al) [9][10][11] in addition to magnesium (Mg) [12,13], titanium [14], steel [15], composite [16], polymer [17], and Cu [2,3,[18][19][20][21][22][23][24][25] since invented in 1991 by The Welding Institute.…”

Effect Of Tool Dwell Time On Friction Stir Spot Welding Of 6013-T6 Aluminum Alloys

“…Özellikle otomotiv sektöründe yaygın bir şekilde kullanılan elektrik direnç kaynağı ile birleştirmesinde sorunlar yaşanılan demir dışı metallerin kaynatılmasında, SKNK yöntemi elektrik direnç kaynağının yerine tercih edilir olmuştur [15]. SKNK üst üste bindirilmiş iki levhaya daldırılan karıştırıcı takımın ve omuzun sürtmesi sonucunda ısının malzemeyi yumuşatması ve birbirine karıştırması prensibine dayanan bir kaynak yöntemidir [15,16]. SKNK yönteminde omuz ve pimden oluşan bir karıştırıcı takım kullanılmaktadır [17].…”