Papers by Keyword: MIG

Abstract: This paper describes the outcomes of practical experiments in the validation of a technology for welding of the Al-Al₂O₃ metal-matrix composite material produced by the internal oxidation method. Technological capabilities are herein considered for argon-arc welding (Tungsten Inert Gas/ TIG) with filler wire and arc welding in a protective inert/active gas medium using a melting electrode (Metal Inert Gas/ MIG) for joining sheets of A6 aluminum alloy-based metal-matrix composite material (MMC). Mechanical properties of welded joints are determined and the fracture macrostructure is investigated. Fracture patterns and tensile strength are shown for different modes of welding procedure for alloy plates of 5, 8 mm in thickness by the TIG method and 25 mm by the MIG method. The macrostructural and mechanical heterogeneity of welded joints is shown. Welds made under optimal conditions are free of any macrodefects. The welded joint strength is up to 96% of the base material strength.

Abstract: In many respects, the advantages of the hybrid welding process Plasma-MIG are explained by the interaction of the arc discharges, which make up it: a plasma discharge and an arc with a consumable electrode (MIG). Knowledge and understanding of the laws of this interaction is very important for the implementation of the process and obtaining good results. The theoretical analysis of the influence of the plasma discharge temperature with non-consumable electrode on the melting of the electrode wire was carried out. The dynamics of the melting of the electrode wire and dynamics of circuit with consumable electrode arc were been investigation. Estimates of the maximum value of the temperature of plasma discharge have been made. These results were used to select welding modes and for carrying out the technological experiments.

Abstract: The aimed of this research is to investigate the effect of T-Joint’s root gap on physical and mechanical properties of weld metal. Low carbon steel were joined in T-joint types using MIG (Metal Inert Gas) with variation of root gap. The root gap used were 0 mm, 3 mm and 6 mm. The physical properties examined with chemical composition, microstructure and corrosion using optical microscope. The mechanical properties were measured with respect to the strength and hardness using Universal testing machine and Vickers Microhardness. The results show that the highest value found in welds with a gap of 3 mm with a value of 163.57 MPa. Hardness value is directly proportional to the tensile strength of the material. The highest value found in welds with root gap of 3 mm, followed by root gap of 6 mm, and 0 mm Hardness values in the welding area is higher than the parent metal and HAZ because the number of Si, Mn and Cu elements in the welding metals are bigger than base metal. Weld with all variation of root gap have a good corrosion resistance because the corrosion rate in welds with various root gap have a value below 0.02 mmpy. Microstructure of weld metals were Accicular ferrite, Widmanstatten ferrite, and grain boundary ferrite, while microstructure of base metal and HAZ were ferrite and perlite.

Abstract: The repair welding of aluminium alloy 6082T6 with two fillers 4043 and 5356 were studied by using MIG welding process with pulse current at frequency 5 Hz. After that, macrostructure and microstructure were investigated and the density of porosity and testing of mechanical properties were determined. The results found that the density of new weld was less than repair weld. The results of mechanical tests showed that the new weld were better than the repair weld.

Abstract: The aim of this research is to predict the tensile strength of the dissimilar aluminium joint by optimizing the parameters in metal inert gas (MIG) welding between aluminium alloys AA6061-T6/AA7075-T6. In this study, the box-behnken design technique and mathematical model were developed by Response Surface Methodology (RSM). Statistical tools such as Design of Experiments (DOE), Analysis of Variance (ANOVA), and regression analysis were used to develop the relationships. Dissimilar aluminium of AA6061-T6 and AA7075-T6 were butt-welded by using MIG with the ER5183 filler. The highest ultimate tensile strength (UTS) of the joint obtained was 178.63 MPa.

Abstract: In manufacturing industry there are many applications for the permanent joint of components of different shapes, but they are also very different in terms of chemical composition and structure [1, 2]. This paper is trying to find technological solutions of assembling by welding of two steels with totally different chemical composition, i.e. carbon steel S235JR + AR and austenitic stainless 316L. The process used for making the heterogeneous joint was Metal Inert Gas (MIG) with flux cored wire, numerically coded 137. The paper presents the effects of welding technology, through heat input, such as hardness. Variations of hardness values determined in the joint areas are presented, as well as the chemical composition of the welded joint obtained using the flux cored wire T 23 12 LPM 1/C1, according to EN ISO 17633 - A.

Abstract: Simulation software based on a finite element method have significantly changed the possibilities of determining welding strains and stresses at early stages of product design and welding technology development. But the numerical simulation of welding processes is one of the more complicated issues in analyses carried out using the Finite Element Method. A welding process thermal cycle directly affects the thermal and mechanical behaviour of a structure during the process. High temperature and subsequent cooling of welded elements generate undesirable strains and stresses in the structure. Knowledge about the material behaviour subjected to the welding thermal cycle is most important to understand process phenomena and proper steering of the process. The study presented involved the SYSWELD software-based analysis of MIG welded butt joints made of 1.0 mm thickness, 5xxx series aluminium alloy sheets. The analysis of strains and the distribution of stresses were carried out for several different cases of fixing and releasing of welded elements.

Abstract: The results of corrosion properties research of aluminum alloy AW 7020 (AlZn5Mg1) welded by friction stir welding (FSW) and MIG were presented. Friction Stir Welding (FSW) – a new technology can be successfully used for butt welding of different types of aluminum alloy sheets. In the paper, the parameters for friction stir welding of sheets made of AlZn5Mg1 [7020] alloy were presented as well as parameters for MIG. Metallographic analysis of bonds showed a proper structural construction of both, the FSW and MIG welded 7020 aluminum alloys.The study was carried out in accordance with the requirements of the ASTM G 106. EIS measurement was performed in three-electrode system in artificial seawater (3.5% NaCl). Impedance studies were carried out at the corrosion potential. Changed voltage signal amplitude in the range ±10 mV and frequency range of changes was as follows: 100 kHz – 0.1 Hz. Atlas 0531 EU & IA potentiostat was used for studies.The results of electrochemical impedance spectroscopy are presented in the form of parameters characterizing the corrosion process. Obtained results were statistically analyzed.The electrochemical impedance spectroscopy studies have shown that the joint welded by FSW has better electrochemical corrosion resistance than the joint welded by MIG and the native material – AW-7020 alloy.Original value are received results of the corrosion properties of new method friction stir welded AlZn5Mg1 alloy compared with traditional MIG method and the native material.

Abstract: The paper presents the research results on the mechanical properties of aluminum alloy 7020 and its FSW and MIG welded joints. For comparison, alloy 5083 – the most currently used in shipbuilding alloy was chosen as well as 5059 – the new high-strength alloy. Besides, the native material alloys there were investigated their joints welded by FSW and MIG – the same methods as alloy 7020. Welding parameters used for the connection of the sheets made of 7020, 5083 and 5059 alloys were presented. Metallographic analysis showed the correct construction of structural bonded joints.Friction Stir Welding (FSW) – a new technology can be successfully used for butt welding of different types of aluminum alloy sheets. FSW method can be an alternative to traditional arc welding methods, especially MIG, which is the most common method of joining aluminum alloys used in shipbuilding. The research was carried out using a static tensile test in accordance with the requirements of the Polish Standards PN-EN ISO 4136:2011 and PN-EN ISO 6892-1:2010. Flat samples cut perpendicular to the direction of rolling were used. The research was conducted at the temperature of +20 oC.Friction stir welded joints of tested alloys have higher strength properties as compared to MIG welded joints. The 7020 alloy has higher strength properties then alloys 5083 and 5059. The yield stress is higher by 14.8% as compared to alloy 5083, and by 11.7% as compared to the alloy 5059. Plastic properties of alloy 7020 are the lowest, but with reserves meet the requirements of classification societies. The joints welded by FSW of alloy 7020 have the highest strength properties of all researched joints – higher then alloys 5083 and 5059 joints welded by FSW and joints of all alloys welded by MIG.

Abstract: In this paper we used ANSYS finite element software to simulate the temperature field in 7a52 aluminum alloy double-arc welding process and analyze the welding seam's forming characteristics. We conducted the welding temperature field numerical simulation in the same welding seam forming conditions by loading heat source of single-arc and double-arc separately, which used gauss heat source model and used voltage, welding current and speed as key parameters. The experiments indicated that the designed double-arc heat source model could generally represent the double-arc welding process. Compared with single-arc welding process, the double-arc welding had higher welding efficiency and narrower heat affected zone. Furthermore, the temperature of double-arc welding pool raised faster. All these advantages could improve the welding efficiency.