Tensile Strength and Macro-microstructures of A6061 CDFW Weld Joint Influenced by Pressure and Holding Time in the Upset Stage

Abstract

This paper aims to analyze the effect of pressure and holding time in the upset stage on tensile strength and macro-microstructures of continuous drive friction welded (CDFW) joints of aluminum alloys A6061. Friction weld specimens were welded using variations of upset pressure (40, 80, 120 MPa). The upset holding time was varied from 3, 10, to 20 seconds. Tensile strength test was conducted based on the AWS standard. The result showed that the higher upset pressure and the longer holding time in the upset stage are able to reduce the porosity of the CDFW weld joint and cause a higher tensile strength of the specimens. Meanwhile, from macro-mic restructures observation results, it was found that the specimen with maximum tensile strength has a wider partly deformed area (ZPD) and finer grains in the center of the specimen longitudinal section compared to those of the specimens with minimum tensile strength. It was occurred due to plastic deformation as the result of the higher pressure and the longer holding time in the upset stage. Fracture surface observation results indicate that in the specimen with a higher upset pressure and a longer holding time, has inflated fracture surface and the fracture zone exists in the heat affected zone, not in the interface like that of the specimen with lower tensile strength due to the lower upset pressure and the shorter holding time.

Effect of Friction Time on the Mechanical and Microstructural Properties of AA6061 Joints by Continuous Drive Friction Welding

“…The welding process was conducted according to the parameters shown in Table II. RS and P f values were taken from [1][2][3]6], which obtained good welding samples. Also, identifying the requirements of an upset stage was investigated by not including any forging in the welded samples and comparing the mechanical properties to non-welded samples.…”

“…Figure 3 shows the tensile sample dimensions. The remaining samples were cut longitudinally, using a precision cutting machine (Pico 75), ground, polished, and etched as per the requirements for such materials [3,18]. Macroscopic graphs were obtained via a digital microscope, while microscopic micrographs were achieved by SEM.…”

“…Friction time was too long as compared to similar studies. The tensile strength of AA6061 CDFW and the related microstructure was investigated in [3] with a constant time of friction but prolonged upset times. The highest tensile strength was achieved when the conditions were set to the highest upset pressure and time.…”

Sifat Mekanis dan Struktur Mikro pada Sambungan Las Gesek Baja SCM415H untuk Aplikasi Poros Roda Belakang

“…Pengujian dilakukan dengan kecepatan beban puntir konstan sebesar 300 N/min, hingga spesimen patah. Hasil pengujian puntir dihitung dengan rumus yang terdapat dalam penelitian Abdulla et al, Tyagita et al dan Tung et al [15][16][17].…”

Tensile Strength Of Round Bar A 6061 Friction Weld Joint Influenced By Changes Room Temperature

“…[ [8]. M. Abdullah F.A dkk, meneliti tentang pengaruh tekanan tempa (upset force) dan waktu penahan (holding time) pada pengelasan Alumunium 6061 dimana hasil yang didapatkan yaitu kekuatan tarik maksimum dari A 6061 sambungan CFDW ditemukan di spesimen dengan tekanan tempa (Upset Force) yakni 120 mpa dan waktu penahanan (Holding Time) yakni 20 detik [9]. Selanjutnya Andrzej Ambroziak, melakukan pengelasan gesek aluminium dengan aluminium paduan dan hasilnya adalah waktu yang lama dapat menyebabkan pembentukan fase intermetalik yang cenderung menyebabkan kerapuhan sambungan [10].…”