scholarly journals Evaluation of Optimization Parameters of Semi-Solid Metal 6063 Aluminum Alloy from Friction Stir Welding Process Using Factorial Design Analysis

2020 ◽  
Vol 4 (4) ◽  
pp. 123
Author(s):  
Chaiyoot Meengam ◽  
Kittima Sillapasa

The semi-solid-metal 6063 aluminum alloy was developed for the automotive industry. The objective of this research was to optimize parameters in friction stir welding process that can provide the highest tensile strength. The ANOVA factorial design was used to analyze rotation speed, welding speed, and tool geometry at different factor levels of experimentation. The results showed that the optimized tensile strength was 120.7 MPa from the cylindrical tool, rotation speed was from 1300 to 2100 rpm, and welding speed less than 75 mm/min in the coefficient of determination R2 was 95.09%, as can be considered from the regression equation. The examination of the stir-zone and thermal mechanical affected zone using SEM and EDX showed that the new recrystallization of the microstructure causes fine grain in the stir-zone, coarse grain in advancing-side thermal mechanical affected zone, and equiaxed grain in the retracting-side thermal-mechanical affect zone. The intermetallic compounds of β-Al5FeSi phase transformation phase were formed to three types, i.e., β″-Al5Fe, Mg2Si, and Al8Fe2Si phase were observed. Moreover, in the stir-zone and thermal-mechanical-affected zone, defects were found such as flash defects, void or cavity defects, crack defects, lack of penetration defects, tunnel defects, kissing bond defects, and dendrite formation defects affecting weldability.

2021 ◽  
Vol 5 (3) ◽  
pp. 88
Author(s):  
Konkrai Nakowong ◽  
Kittima Sillapasa

The semi-solid metal (SSM) 5083 aluminum alloy was developed for part manufacturing in the marine shipbuilding industry. This study aimed to optimize the parameters for the friction stir welding process of SSM 5083 aluminum alloy using the Taguchi and analysis of variance (ANOVA) techniques. Our analyses included tensile strength, hardness value, and the microstructure. The results revealed that the optimal parameters obtained for the tensile strength and hardness value in the stir zone (SZ) were A1B1C2 (1000 rpm, 10 mm/min, with a threaded cylindrical tool) with a tensile strength of 235.22 MPa and A2B1C2 (1200 rpm, 10 mm/min, with a threaded cylindrical tool) with a hardness value of 80.64 HV. According to the results obtained by ANOVA, it was found that the welding speed was the most significant process parameter in terms of influencing the tensile strength. Contrarily, no parameter influenced the hardness at a 95% confidence level. The examination using scanning electron microscopy (SEM) and an energy dispersive X-ray spectroscope (EDS) revealed an elongated grain structure and a void defect at the pin tip on the advancing side (AS) in the SZ. The particle distribution was uniform with Al2O3 and small porous SiO2 phases. Moreover, the quantities of C, O, Al, F, and Mg decreased.


2020 ◽  
Vol 863 ◽  
pp. 85-95
Author(s):  
Truong Minh Nhat ◽  
Truong Quoc Thanh ◽  
Tu Vinh Thong ◽  
Tran Trong Quyet ◽  
Luu Phuong Minh

This study presents conducted heat simulations and experimental jointing flat-plate of aluminum alloy 6061 and SUS 304. Temperature is simulated by the COMSOL software in three states: (1) Preheat the Friction Stir Welding (FSW) by TIG welding, (2) Thermal contact resistance between Aluminium and steel, and (3) The welding process using stiring friction is simulated. The simulations intended to predicting the temperature which is used for preheat and welding process to ensuring the required solid-state welding. The temperature is also determined and checked by a thermal imager comparing with simulation results. Besides, the results of tensile strength is carried out. The Box - Behnken method is used to identify the relationship between the welding parameters (rotation, speed and offset), temperature and tensile strength. The maximum tensile strength is 77% compared to the strength of aluminum alloy. The optimal set of parameters for the process is n = 676 rpm, v = 46 mm / min and x = 0.6 mm. The optimizing welding parameters to achieving good quality of welding process are described. SEM images to determine some properties of welding materials. This is also the basis for initial research to identify some defects in welding of two different materials (IMC thickness and interconnected pores) and the cause of these defects.


2013 ◽  
Vol 372 ◽  
pp. 478-485 ◽  
Author(s):  
Chaiyoot Meengam ◽  
Muhamad Tehyo ◽  
Prapas Muangjunburee ◽  
Jessada Wannasin

The aim of this research is to study the influence of welding parameters on the metallurgical and mechanical properties of friction stir welded butt joints of dissimilar aluminum alloy sheets between Semi-Solid Metal (SSM) 356-T6 and AA6061-T651 by Friction Stir Welding (FSW). The base materials of SSM 356-T6 and AA6061-T651 were located on the advancing side (AS) and on the retreating side (RS) respectively. The base materials were joined under different tool rotation speeds and welding speeds. The material flows from SSM 356 and AA6061-T651 were clearly visible in the weld nugget. In addition, the mixtures of fine equiaxed grain were observed in the stir zone. The increase in tool rotation speed results in the increase in tensile strength of the joints. As for welding speed associated with various tool rotation speeds, an increase in the welding speed affected lesser the base materials tensile strength up to an optimum value; after which its effect increased. Tensile elongation was generally greater at greater tool rotation speed. An averaged maximum tensile strength of 206.3 MPa was derived for a welded specimen produced at the tool rotation speed of 2,000 rpm associated with the welding speed of 80 mm/min. In the weld nugget, higher hardness was observed in the stir zone than in the thermo-mechanically affected zone. Away from the weld nugget, hardness levels increased back to the levels of the base materials.


10.29007/6xnv ◽  
2018 ◽  
Author(s):  
Kamlesh Dhansukhlal Bhatt ◽  
Nikul Patel ◽  
Vishal Mehta

Magnesium & its alloys are flammable for conventional fusion welding process. This adverse effect can be eliminated by a non-fusion solid state welding process, established by The Welding Institute (TWI) in 1991, called friction stir welding (FSW). This is applied in this investigation for joining two plates together by using non-consumable tools (three pin profiles) between two abutting plates of magnesium alloy AZ91 having 6 mm thickness. FSW process joins the plates with certain advantages such as low distortion, no shielding gas required, fine recrystallized microstructure, no fumes liberated during the process, etc. In Friction stir welding, process parameters such as welding speed, tool rotation speed, tool dimensions and axial force play an important role during the process. In the present work, the 6 mm thick plates of the said alloy are welded at traverse speed of 28 mm/min to 56 mm/min with tool rotation speed ranging from 710 rpm to 1400 rpm. Tensile strength testing & simulation of peak temperatures has been carried out for establishing correlationship between best parameters from the selected ones with temperature profiles obtained by those parameters for giving optimum structure-property relationship using different pin profiles.


Author(s):  
J.C. Verduzco Huarez ◽  
R. Garcia Hernandez ◽  
G. M. Dominguez Almaraz ◽  
J.J. Villalón López

This research work focuses on the study of the improvement of mechanical properties, specifically the tensile strength of 6061-T6 aluminum alloy on prismatic specimens with 9.5 mm thickness that has been subjected to friction stir welding process and two heat treatments; solubilized and aging before or after the welding process. Three cases studied and evaluated were, welding of the base material without heat treatment (BMW), solubilized heat treatment and partial aging of the base material before welding (HTBW), and heat treatment of solubilized and aging of the base material after welding (HTAW). The obtained results show an increase of about 10% (20 MPa) of tensile strength for the HTBW process, compared to BMW case. In addition, for the case of HTAW, the obtained tensile resistance presents a joint efficiency of 96%, which is close to the tensile strength of the base material (»310 MPa).


Author(s):  
Truong Minh Nhat ◽  
Truong Quoc Thanh ◽  
Tran Trong Quyet ◽  
Luu Phuong Minh

Friction stir welding exploits its solid-state process behavior to join aluminum to steel, which differs in thermal and mechanical properties, and where a combination of these metallic alloys by fusion welding prompts a deleterious reaction as a result of the melting and resolidification phases. Recently, hybrid techniques have been employed in FSW for several materials and alloys, particularly for steel–steel joining. These methods are generally aimed to pre-heat the steel plate materials. This study presents conducted heat simulations and experimental jointing flat-plate of aluminum alloy 6061 and SUS 304. Temperature is simulated by the COMSOL software in three states: (1) Preheat the Friction Stir Welding (FSW) by TIG welding, (2) Thermal contact resistance between aluminum and steel, and (3) The welding process using stirring friction is simulated. The simulations intended to predict the temperature, which is used for the preheating and welding process to ensuring the required solid-state welding. The temperature is also determined and checked by a thermal imager comparing with simulation results. Besides, the results of tensile strength are carried out. The Box - Behnken method is used to identify the relationship between the welding parameters (rotation, speed, and offset), temperature, and tensile strength. The maximum tensile strength is 77% compared to the strength of the aluminum alloy. The optimal set of parameters for the process is n = 676 rpm, v = 46 mm / min and x = 0.6 mm. The optimizing welding parameters to achieving a good quality of the welding process are described. SEM images to determine some properties of welding materials. This is also the basis for initial research to identify some defects in the welding of two different materials (IMC thickness and interconnected pores) and the cause of these defects.


2014 ◽  
Vol 597 ◽  
pp. 253-256 ◽  
Author(s):  
Nurul Muhayat ◽  
Triyono ◽  
Bambang Kusharjanta ◽  
Radian T. Handika

The effects of preheat temperature on mechanical properties and the microstructure of friction stir welded (FSW) aluminum alloy 5052 joints were studied in the present work. Heated air from Hot Gun was applied in front of the FSW tool to give the preheat on friction stir welding process. Preheat temperature was set 150°C, 250°C and 300°C. Mechanical properties were correlated and analyzed according to tensile strength, macro and microstructure. Defect free weldswere obtained at all preheat variations. The increasing preheat temperature produced the coarser grain size, it influencedthe little decrease both the tensile strength and hardness of joints.


2018 ◽  
Vol 14 (3) ◽  
pp. 1-11 ◽  
Author(s):  
Samir Ali Amin ◽  
Mohannad Yousif Hanna ◽  
Alhamza Farooq Mohamed

Bobbin friction stir welding (BFSW) is a variant of the conventional friction stir welding (CFSW); it can weld the upper and lower surface of the work-piece in the same pass. This technique involves the bonding of materials without melting. In this work, the influence of tool design on the mechanical properties of welding joints of 6061-T6 aluminum alloy with 6.25 mm thickness produced by FSW bobbin tools was investigated and the best bobbin tool design was determined. Five different probe shapes (threaded straight cylindrical, straight cylindrical with 3 flat surfaces, straight cylindrical with 4 flat surfaces, threaded straight cylindrical with 3 flat surface and threaded straight cylindrical with 4 flat surfaces) with various dimensions of the tool (shoulders and pin) were used to create the welding joints. The direction of the welding process was perpendicular to the rolling direction for aluminum plates. Tensile and bending tests were performed to select the right design of the bobbin tools, which gave superior mechanical properties of the welded zone.  The tool of straight cylindrical with four flats, 8 mm probe and 24 mm shoulders diameter gave better tensile strength (193 MPa), elongation (6.1%), bending force (5.7 KN), and welding efficiency (65.4%) according to tensile strength.     


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