ER5356 Filler Research Articles

Weldability of A7075-T651 and AZ31B dissimilar alloys by MIG welding method based on welding appearances

It is not recommended to weld aluminium and magnesium dissimilar alloys using fusion welding method because of the formation of AlmMgn type intermetallic brittle compounds like Mg2Al3, Mg17Al12 etc. in the welding joint. These brittle compounds deteriorate the mechanical properties of the joint. But so far, insufficient researches have been attempted to stop the formation of AlmMgn type intermetallic brittle compounds in fusion welding method. The aim of this research work was to investigate on the weldability between A7075-T651 and AZ31B dissimilar alloys based on welding appearances and study the formation of intermetallic brittle compounds at the joint. In this research, A7075-T651 and AZ31B alloys were welded using ER5356 filler wire in MIG welding method in butt configuration. 100% argon was used as shielding gas. The results showed that, most of the welding appearances were moderate. The macroscopic investigation at all welding cross section showed that a lot of AlmMgn intermetallic brittle compounds were formed at the interface between weld seam and AZ31B parent metal side which caused macro cracks. A good number of macro pores were also observed at AZ31B parent metal side. These cracks and pores could easily cause the failure of the joint at very low stress.

English

Aluminum-stainless steel dissimilar welding processes yield unwanted disadvantages in the weld joint due to the large difference between the aluminum-stainless steel sheets’ melting points and the nearly zero solid solubility between these two metals. Aluminum AA6061 and stainless steel SUS304 were lap-welded by using Metal Inert Gas (MIG) welding with aluminum filler ER5356 (Group 1) and stainless steel filler ER308LSi (Group 2). The effects of the welding voltage and type of filler metals used on the weld joints were studied. The welding voltage had a significant effect on the welding process, as higher voltage resulted in poorer appearance of the weld joint and led to defects for both groups, such as porosity and incomplete fusion. The microstructure for Group 1 joints shows enrichment of Si particles, which benefited the joint properties as it increased the strength of the metal. The stainless steel substrates that spread into the aluminum side are much greater in volume for Group 1 than for Group 2 joints. Meanwhile, the microstructure of Group 2 joints (using ER308LSi filler) consists of chromium carbide precipitation which yields a high hardness value, but a brittle structure. The hardness values of the welded seams in Group 1 and Group 2 range from 60 to 100 HV and 160 to 230 HV, respectively. The fracture in the tensile test yielded the highest tensile strength of 104.4 MPa with aluminum fillers. The tensile strength of Group 1 joints ranging from 47.8 to 104.4 MPa was collectively higher than Group 2 joints, between 20.24 to 61.76 MPa. Based on the investigation throughout this study, it can be concluded that the welding voltage of 18 V and aluminum filler ER5356 is the optimum filler in joining the dissimilar metals aluminum AA6061 and stainless steel SUS 304.

Microstructure Characteristics and Properties of Mg/Al Dissimilar Metals Made by Cold Metal Transfer Welding with ER4043 Filler Metal

Abstract AZ31B magnesium alloy and 6061 aluminum alloy were joined in stable welding process by cold metal transfer welding with ER4043 as filler metal. The microstructure, morphology and phase composition of the welded joints were studied by OM, SEM, EDX and XRD. The results show that weld metal and aluminum substrate are combined with a good interface, while weld metal and Mg substrate are combined with a epitaxial solidification area where the intermetallic compounds of Mg 2 Al 3 , Mg 17 Al 12 and Mg 2 Si are generated. The micro-hardness distribution shows a decreasing trend from Mg side to Al side in the weld. The joint is brittle fractured in the fusion zone of Mg side, where plenty of Mg 2 Si, Mg 2 Al 3 and Mg 17 Al 12 are distributed continuously.

Effect on the Microstructure and Mechanical Properties of the Electromagnetic Stirring during GMA Welding of 2205 DSS Plates

Plates, 6.3 mm thick, of 2205 duplex stainless steel (DSS) were gas metal arc welded (GMAW) under the application of an axial magnetic field (0 to 15 mT) with an ER-2209 filler wire using a gas mixture of 98%Ar + 2%O2. Microstructural characterization of the welds revealed that electromagnetic stirring (EMS) increases the content of austenite in both weld center and high temperature heat affected zone (HTHAZ). It induced a grain refining effect during freezing of the ferritic matrix which in turn enabled more sites for nucleation of austenite. This mechanism of solidification was reflected in an increase in the mechanical strength of the welds. Besides, the extent of the HTHAZ was reduced and its microhardness increased when applying the external magnetic field. It is believed that the vibration induced in this region favored the regeneration of austenite in the ferritized HTHAZ enhancing the balance of phases.

The Effect of Double Sided Gas Metal Arc Weld with ER4043 and ER5356 Filler Metals on AA 6061-T6 Plates

The Effect of Double Sided Gas Metal Arc Weld with ER4043 and ER5356 Filler Metals on AA 6061-T6 Plates

Combined welding of Austenitic and Ferritic Stainless steel

This paper contains experiences in the welding of Austenitic and Ferritic stainless steel with combination of welding process GTAW and SMAW. This investigation characterized the mechanical and chemical properties of weld metal in the Austenitic and Ferritic stainless steel. The selection of filler metal for welding the Austenitic and Ferritic stainless steel is based on the composition of the base metal (SA240 UNS S32304). For root welding GTAW processes ER2209 filler wire and subsequent layer SMAW processes with electrode with basic flux E2209-17selected for this investigation. These investigations are complains with ASME boiler pressure vessels codes. The principal goal of this presentation was to provide the solution for combined welding of Austenitic and Ferritic stainless steel to the application of fabrication of desalination tank and ship building.

Post-Weld Oxidation Behavior of AA6061 Al Alloy

Welded AA6061 Al alloy using ER5356 (Al-5Mg) filler was oxidized in flowing air gas for 40hrs at 600oC at a total pressure of approximately 1 atm. The morphology and microstructure of welded joint after exposure was characterized by using optical metallurgy microscopy and Scanning Electron Microscope (SEM). Different oxide morphologies and textures were observed on parent and fusion metal due to the differences of the alloying element. The oxidation mechanism represented a complex reaction occur where the morphology and phase formation of the oxide shows the protective oxide scales showed the protective oxide were developed on parent metal side, meanwhile non-protective oxide scale formed on fusion metal of the welded Al alloy. It can be concluded that the welded area failed to resist oxidation behavior compared to the parent metal. The differ results are discuss in term of microstructure changes caused by high temperature oxidation exposure and alloying element.

Oxidation Effect of Welded AA6061 Al Alloy Using ER5356 Filler Metal

Test material of welded AA6061 Al alloy using ER5356 (Al-Mg-Si) filler metal was oxidized inflowing air gas for 40hrs at 600oC at a total pressure of approximately 1 atm. The morphology andmicrostructure of oxide formation on welded Al alloy was characterized using SEM and EDAX.Different oxide morphologies were observed on parent and fusion metal due to the differences of thealloying element. The oxidation mechanism represented a complex reaction where the morphology andphase formation of the oxide shows the protective oxide were developed on parent metal side, whilenon-protective oxide formed on fusion metal of the welded Al alloy.

Microstructure and Mechanical Properties of Aluminum/Stainless Steel Joints Welded by Different Weld Heat Input

Dissimilar metals joints between aluminum and zinc-coated steel were joined by CMT machine with ER4043 filler metal. The microstructure and mechanical properties of the joints obtained with different heat input were analyzed. The results showed that the thickness of interfacial intermetallic compound was determined by the welding heat input. Tensile specimens were broken in HAZ of aluminum base metal and the tensile strength of the joint can reach 122.3MPa.

The Effect of Filler ER4043 and ER5356 on Porosity Distribution of Welded AA6061 Aluminum Alloy

The filler metal used during welding process is believed to play an important role on porosity formation in aluminium alloy welded. The present investigation is aimed to study the effect of different fillers ER4043 (Al-5%Si) and ER5356 (Al-5%Mg) on porosity formation of AA6061 alloy welded joints. Butt-joint welds were made on 6 mm thick plates using 21 – 22 V arc voltages by using Gas Metal Arc Welding process (GMAW). The hardness profile of each types of AA6061 welded joints for both fillers were characterized by the Vickers microhardness test. In order to study the formation and distribution of porosity, the images of analysis were obtained using the X- ray CT-Scan. It was observed that, more porosities were found in the alloy AA6061 using ER4043 compared to ER5356 filler metals with the percentage area value of porosity about 18.3 and 8.4%, respectively. The hardness profile of ER5356 and ER4043 welded materials exhibited the similar hardness pattern profile. It is proposed that Si and Mg contents in the filler metal could play significant role in the distribution of porosity. No significant effect was observed on the hardness profile for both filler metals of welded materials.

Enhanced SCC resistance of AA7005 welds with appropriate filler metal and post-welding heat treatment

Stress corrosion cracking (SCC) resistance for weldment of Al–Zn–Mg alloys is enhanced with appropriate filler metal and post-welding heat treatment while maintaining the weld strength integrity. Tungsten insert gas (TIG) arc welding is used to join the AA7005-T4 plates with three high-Mg fillers, ER5183, ER5556 and ER5356. Four heat treatments, NA (natural ageing), T6, T73, and RRA, were applied to the welded plates. Micro-hardness test, tensile test and stress corrosion test were conducted on the heat-treated specimens. Differential scanning calorimetry (DSC) analyses and transmission electron microscopy (TEM) observations were also performed on the specimens cut from the fusion zone. For the three high-Mg filler metals, only the ER5356 filler with low Mn content showed improvement in the tensile property after different post-welding heat treatments. Weld strength improvement were ideal for the T7 post-welding heat treatment. No improvements were observed for the ER5183 and ER5556 filler wires. The ultimate tensile strength of ER5183, ER5556 and ER5356 weld were found to fall within the, respective, ranges of 250–280, 270–300, and 280–360 MPa corresponding to the different heat treatments. Post-welding heat treatment improves the SCC resistance of welds made with ER5356 and specimens with T7 and RRA heat treatments. DSC analyses showed that only the specimen fabricated from the weld made with ER5356 has an endothermic dissolution reaction peaked at 141 °C. The TEM images from the fusion zone (FZ) of T7 and RRA welds with ER5356 filler wire showed similar micro-structure and distribution of precipitates. They both have relatively large and non-continuous precipitates at the grain boundary. The size of precipitates differed in the matrix. The combination of ER5356 filler metal and post-welding T7 treatment can offer the AA7005 weld with better SCC resistance and high tensile strength.

Mechanical Properties of 5083 Aluminium Welds after Manual and Automatic Pulsed Gas Metal Arc Welding Using E5356 Filler

Semi-automatic and automatic pulsed gas metal arc welding (GMAW) of aluminium alloy 5083 with ER5356 filler wire causes considerable softening in the weld. The tensile strength of dressed automatic welds approaches that of the base metal, but the stress concentration caused by the weld toe in undressed semi-automatic welds reduced the tensile strength significantly. Fully automatic welds displayed improved fatigue properties compared to semi-automatic welds.

Preliminary assessment of the effects of the application of an axial magnetic field during GMA welding of Al-6063-T6

Plates of Al 6063-T6 (6.35mm thick) were welded using an ER-5356 filler wire. The aim of the experiments was to assess the effects that yield the induction of an axial magnetic field (AMF) during gas metal arc (GMA) welding on the grain structure of the weld metal and on the mechanical properties of the welded joint. Magnetic fields between 0 to 15mT were induced by using a coil which was fed with different current intensities by an external power source. Plots of the grain size distribution showed that applying low magnetic fields homogenizes the grain structure of the weld metal and suppresses the typical columnar-dendritic growth from partially melted grains at the fusion line. The mechanisms involved in these phenomena are discussed with the aid of finite element analysis. Transverse microhardness profiles of the welds revealed a reduction in the loss of hardening in the heat affected zone (HAZ). The loss of hardening after fusion welding in heat treatable aluminum alloys is known as overaging and it is the result of coarsening and transformation of the strengthening phase [1]. It is thought that an electromagnetic interaction between the external magnetic field applied and the inherent magnetic field generated by the direct current of the welding process alters the diffusion process delaying over aging kinetics in the HAZ.

Macro and Microstructural Effects of the Application of an Induced Axial Magnetic Field During the Deposition of Aluminum Weld Beads

ABSTRACTIn this work, aluminum weld beads were deposited on aluminum plates of commercial purity (12.7 mm thick), using an ER-5356 filler wire. The aim of the experiments was to assess the effects that yield the induction of an axial magnetic field (AMF) during the application of the weld beads using the direct current gas metal arc welding process (DC-GMAW). An external power source was use to induce magnetic fields between 0 to 28 mT. The effects of the magnetic fields were assessed in terms of the macrostructural features of the deposits, morphology of the grain structure, grain size and grain size distribution in the weld metal. Macrostructural characteristics of the weld beads revealed that increasing the intensity of the magnetic induction to produce a magnetic field above 14 mT, leads to a significant loss of feeding material and there is a tendency of the deposits to increase their width and reduce penetration. Perturbation of the weld pool induced by the application of the AMF noticeably modified the grain structure in the weld metal. In particular, for the intensities of 5 and 14 mT, columnar growth was essentially non-existent. Grain size distribution plots showed, generally speaking, that the use of magnetic fields is an efficient method to produce homogeneous grain structures within the weld metal. Finite element analysis was used to explain the weld bead geometry with the intensity of the magnetic field.

A comparative study of the mechanical properties of 6061-T6 GMA welds obtained by the indirect electric arc (IEA) and the modified indirect electric arc (MIEA)

Plates of a 6061-T6 aluminium alloy with 12.7 mm in thickness were welded with the gas metal arc welding process (GMAW) using three different joint designs; a single V groove butt joint, the indirect electric arc (IEA) joint and the modified indirect electric arc joint (MIEA). The later is a modification of the IEA joint which requires preheating of the plates prior welding to achieve full penetration with an ER-4043 filler wire. The single V groove joint was welded at ambient temperature with four welding passes whereas the IEA and MIEA joints were welded with preheating at 50, 100 and 150 °C in a sole pass. A comparison of the macrostructural characteristics and mechanical performance showed that joining this alloy is feasible with the different joint geometries. However, the thermal affection for the single V groove joint is quite large leading to a severely overage zone in the base metal that profoundly affects the mechanical strength of the welded joint. This effect was less dramatic for the IEA and MIEA joints due to lower heat inputs, but only the mechanical strength of the MIEA weld was above the permissible values indicated by international standards for welded joints of the 6061-T6 alloy.

Effect of Joint Design on Mechanical Properties of AL7075 Weldment

The effects of joint design on the mechanical properties of AL7075-T6 aluminum sheet were studied on the latest automated gas-tungsten arc-welding system. Using ER5356 filler metal, full-penetration welds were made on workpieces with various included joint angles. Testing of the mechanical properties of the joints was done in the as-welded, naturally aged, and postweld heat-treated conditions. The results show that by using crack-resistant filler, and by selecting the proper joint design and postweld heat treatment, strong, dependable welds can be produced on thin AL7075 sheet material. An elasticity model of the weld joint was established to help understand the mechanical behavior of the joints. An undermatched joint design is shown to be capable of achieving a joint strength that matches the strength of the base alloy.