Transient Liquid Phase Bonding (TLPB) process of semi-solid metal 7075 aluminum alloys (SSM7075) using 50 μm thick of ZA27 zinc alloys as interlayers for the experiment were carried out under bonding temperatures of 480 and 540 °C and bonding times of 30, 60, 90 and 120 min respectively. In the bonding zone, the semi-solid state of ZA27 zinc alloy interlayers were diffused into the SSM7075 aluminum alloy. Examination of the bonding zone using Scanning Electron Microscope (SEM) and Energy-dispersive X-ray spectroscopy (EDS) showed that the precipitation of the intermetallic compound of η(Zn–Al–Cu), β(Al2Mg3Zn3), T′(Zn10Al35Cu55) and MgZn2 were formed in the bonding zone. The better homogenized microstructure in the bonding zone was formed when increasing bonding time and bonding temperature. The highest bonding strength was recorded at 17.44 MPa and average hardness was at 87.67 HV with the bonding time of 120 min and temperature at 540 °C. Statistically, the coefficient of determination analysis of bonding strength data was at 99.1%.

Abstract. The aim of this study is to investigate joining parameters that affect microstructure and mechanical properties of diffusion bonding technique in dissimilar joints between SSM7075 and SSM356 aluminum alloys. Diffusion bonding methods were investigated by joining parameters as follows: contact pressure at 3 MPa, holding time 60 and 120 minutes and temperature at 673, 723, 773 and 823 K respectively, under argon atmosphere at 4 liters per minute. After experiments, the results of the investigation have shown that a condition used contact pressure at 3 MPa, holding time 120 minutes, and temperature at 773 K is complete and no defects and voids. Examination of the joint region using SEM and EDX showed that the microstructure in weld zone after welding is globular structure, and eutectics phases of two materials diffuse together. In weld zone, it was found that formation of eutectic phases has Al2CuMg, Mg2Si and Al2Mg2Zn3 phases along the bond interface, distributed throughout bond interface. The tensile tested showed the maximum tensile strength of 94.94 MPa. The hardness was tested for optimum hardness value, 121.20 HV. However, the heat during welding, resulting in precipitation within the aluminum matrix (α-Al), led to increased hardness after diffusion bonding.

Abstract-This research aims study parameters in the dissimilar butt-joint of AA1100 aluminum alloy with C3604 brass by using a FSW process. The parameter is rotation speed 660, 1110 and 1320 rpm, travel speed at 80 and 160 mm/min, lead angle 3 degree and pin tool cylindrical shape from JIS-SKH 57 carbon steel. The experimental results show that FSW between both materials bonded together very well. The increase of rotation speed with lower travel speed is likely to increase the tensile strength as well. The highest tensile strength was 49.25 MPa from rotation speed 1320 rpm and travel speed at 80 mm/min. On the other hand, at lower rotation speed and a high travel speed, a low tensile strength of 25.35 MPa was observed from rotation speed 1110 rpm and travel speed at 160 mm/min. After FSW, the hardness properties were changed in FZ due to the flow of meat material, which their average hardness was around 53 HV. The microstructure of both materials was changed in FZ forming friction force and thermal temperature, it also found that the joint are alternately flow of meat material of both types.Keyword -Friction Stir Welding, C3604 Brass, AA1100 Aluminum Alloy, Dissimilar Welding. These processes provide many advantages; especially FSW process due to filler metal, non-consumable tool, low power consumption, joint high strength, ability to weld different materials and environmentally friendly. This FSW process was patented in 1991 by The Welding Institute (TWI) of Cambridge, England. INTRODUCTION[6] However, the FSW process often used aluminum alloy or other materials which their melting points are not high. This is because they rely on heating from friction force. In general, FSW process is used for welding between different materials, which is easier than liquid state welding process. The mechanism of FWS process starts by a rotating tool plunged into specimens until the tool shoulder is contacted on the surface of the specimens. Then, the heat from the friction softens two different materials and the rotation speed generates the flow of meat material until the two materials bonded together. The parameters for FSW process are rotation speed, travel speed, plunge load or plunge position, tool lead angle and tool design/geometry., etc.[7] The AA1100 aluminum alloy is commonly used due to its good thermal properties and easy to acquire [8]. Likewise, C3604 brass is a popular material due to its good electrical properties and corrosion resistant [9]. For welding both materials together, it is difficult but interesting because chemical compositions, microstructure and melting point are totally different. Thus, this research studied the optimum parameters that affect joint welding of AA1100 aluminum alloys with C3604 brass by FSW process. This interesting result from changes in the structure of joint area and mechanical properties after welding was observed. EXPERIMENT Material preparationThe C3604 brass and wrought AA1100 aluminum alloy were materials used for this FSW process. These specimens were prepared to be sheets...

The purpose of this research was to study the diffuse element and mechanical property of Semi-solid casting (SSC) 7075 and 6061 Al alloy from diffusion welding (DW). The results found that Zn elements were successfully diffused. Mg2Si and MgZn2 intermetallics were precipitated from plate-like shape to flake shape. The high bonding temperature and bonding time caused diffuse elements distributed throughout the material. The mechanical property showed that the maximium average tensile strength was 76.80 MPa from bonding temperature at 723 K and 120 min bonding time. The hardness in bonded line was around 63 HV to74 HV.

The objective of this research was to investigate variables that affected the adhesion of the welded joints for TWBs with FSW in the SSM 2024 aluminum alloys. The results clearly showed that there was a good adhesion of the samples in every experiment. Longitudinal voids can also been found on the top surface of some variables. The average size of cross-links structure of Al2Cu phase (β phase) in SZ, broken into smaller pieces, was around 4 to 7 μm and evenly mixed with alpha phase (α phase). The effect of fracture of Al2Cu phase promoting better mechanical properties. The appropriate tensile strength from the experiment came from variables at the work angle at 15o, rotation speed at 2720 rpm, and welding speed 60 mm/min which provided maximum tensile strength value at 205.0 MPa and the maximum average hardness at 132.4 HV, higher than the weld region. The assessment results showed that the differences in welding variables resulted in different mechanical properties.