Microstructural and Mechanical Properties of a Solid-State Additive Manufactured Magnesium Alloy

2021 ◽  
pp. 1-21
Author(s):  
Thomas Robinson ◽  
Malcolm Williams ◽  
Harish Rao ◽  
Ryan P. Kinser ◽  
Paul Allison ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Solid State ◽  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Process Parameters ◽  
Weight Ratio ◽  
Structural Components ◽  
Friction Stir ◽  
Magnesium Alloy Az31b

Abstract In recent years, additive manufacturing (AM) has gained prominence in rapid prototyping and production of structural components with complex geometries. Magnesium alloys, whose strength-to-weight ratio is superior compared to steel and aluminum alloys, have shown potential in lightweighting applications. However, commercial beam-based AM technologies have limited success with magnesium alloys due to vaporization and hot cracking. Therefore, as an alternative approach, we propose the use of a near net-shape solid-state additive manufacturing process, Additive Friction Stir Deposition (AFSD), to fabricate magnesium alloys in bulk. In this study, a parametric investigation was performed to quantify the effect of process parameters on AFSD build quality including volumetric defects and surface quality in magnesium alloy AZ31B. In order to understand the effect of the AFSD process on structural integrity in the magnesium alloy AZ31B, in-depth microstructure and mechanical property characterization was conducted on a bulk AFSD build fabricated with a set of acceptable process parameters. Results of the microstructure analysis of the as-deposited AFSD build revealed bulk microstructure similar to wrought magnesium alloy AZ31 plate. Additionally, similar hardness measurements were found in AFSD build compared to control wrought specimens. While tensile test results of the as-deposited AFSD build exhibited a 20 percent drop in yield strength, nearly identical ultimate strength was observed compared to the wrought control. The experimental results of this study illustrate the potential of using the AFSD process to additively manufacture Mg alloys for load bearing structural components with achieving wrought-like microstructure and mechanical properties.

Estimation and Comparison of Welding Responses Using MRA, GMDH and ANN Technique of Al6061 and Al7075 Material in FSW

2019 ◽  
Author(s):  
Ugrasen Gonchikar ◽  
Holalu Venkatadasu Ravindra ◽  
Prathik Jain Sudhir ◽  
Umeshgowda Bettahally Mahadevegowda ◽  
Shankarnarayan Maskibail Suresh
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Friction Stir Welding ◽  
Solid State ◽  
Ultimate Tensile Strength ◽  
Process Parameters ◽  
Alloying Elements ◽  
Friction Stir ◽  
Al 6061 ◽  
Al 7075

Abstract Friction Stir Welding (FSW) is a solid state welding which uses non-consumable steel rod to weld two materials. Friction stir welding is an emerging process which is based on frictional heat generated through contact between a non-consumable rotating tool and work piece. Friction stir welding technique possesses several advantages over other conventional types of welding due to the fact that process is carried out in solid state. Removal of melting helps in minimizing porosity and eliminates oxide inclusion. In this study, we focus on the optimization of the process parameters in friction stir welding of two different aluminium alloys (6061, 7075) using Taguchi method of experimental design. Al 6061 and Al 7075 are the two different alloys of aluminium. Among these Al 7075 has mechanical properties nearly double than that of Al 6061, but Al 6061 is used more extensively than Al 7075 because of its low cost. Al 6061 and Al 7075 being alloys of aluminium varies in the composition of alloying elements used in their manufacturing. Al 6061 has magnesium and silicon as its major alloying elements whereas Al 7075 has zinc as its primary alloying element. Al 6061 comes with medium to high strength, exhibit good toughness and surface finish, excellent resistance to corrosion at environmental conditions and another important property is its good weldability. Al 7075 being stronger than Al 6061 lacks in its resistance to corrosion and has poor weldability. Al 6061 is readily weldable but Al 7075 is not, because it is prone to micro-cracking during welding. This study also describes the relation between process parameters and their response of friction stir weld on ultimate tensile strength and hardness of composite materials using mathematical models. The process parameters considered are rotational speed, welding speed and number of passes. Different methodologies are used to develop the models to predict the responses and mechanical properties such as ultimate tensile strength and hardness. The objective of Multiple Regression Analysis (MRA) is to construct a model that explains as much as possible, the variability in a dependent variable, using several independent variables. Group Method of data Handling Technique (GMDH) is a family of inductive algorithms for computer-based mathematical modelling of multi-parametric datasets that features fully automatic structural and parametric optimization of models. GMDH is used in such fields as data mining, knowledge discovery, prediction, complex systems modelling, optimization and pattern recognition. As the machining process is non-linear and time dependent, it is difficult for the traditional identification methods to provide an accurate model. Compared to traditional computing methods, the Artificial Neural Network’s (ANN) are robust and global. Estimation and comparison of machining responses were carried out by MRA, GMDH and ANN.

Effect of Travel Speed on Quality and Welding Efficiency of Friction Stir Welded AZ31B Magnesium Alloy

2018 ◽  
Vol 7 (3.17) ◽  
pp. 94 ◽  
Author(s):  
Amir Hossein Baghdadi ◽  
Nor Fazilah Mohamad Selamat ◽  
Zainuddin Sajuri ◽  
Amir Hossein Kokabi
Keyword(s):  
Grain Size ◽  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Rotation Speed ◽  
Weight Ratio ◽  
Travel Speed ◽  
Welding Parameters ◽  
Az31b Magnesium Alloy ◽  
Friction Stir ◽  
Fsw Parameters

Weight reduction is one of the most concerning issues of automotive and aircraft industries in reducing fuel consumption. Magnesium (Mg) alloys are the lightest alloys which can be used in the structure due to low density and high strength to weight ratio. Developing a reliable joining process of magnesium alloys is required due to limited ductility and low workability at room temperature. Friction stir welding (FSW) is a solid-state welding process that can be performed to produce sound joints in magnesium alloys. Researchers have performed investigations on the effect of rotation and travel speeds in FSW of AZ31B magnesium alloy. However, there is lack of study on the FSW parameters, i.e. travel speed below 50 mm/min and rotation speed lower than 1000 rpm. In this research, FSW of AZ31B magnesium alloy was performed at a constant rotation speed of 700 rpm and varied travel speeds below 50 mm/min. The results showed the development of finer grain size in stir zone with increasing of welding travel speed from 20 mm/min to 40 mm/min. It was found that the finer grain size improved the mechanical properties while maintaining the elongation at different welding parameters.  

scholarly journals The Effects of SiC Particle Addition as Reinforcement in the weld Zone during Friction Stir Welding of Magnesium Alloy AZ31B

2016 ◽  
Vol 3 (3) ◽  
Author(s):  
Md. Aleem Pasha ◽  
Dr. P. Ravinder Reddy ◽  
Dr. P. Laxminarayana ◽  
Dr. Ishtiaq Ahmad Khan
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Magnesium Alloy ◽  
Welded Joints ◽  
Weld Zone ◽  
Mg Alloy ◽  
Friction Stir ◽  
Sic Particles ◽  
Magnesium Alloy Az31b ◽  
Sic Particulates

<div><p><em>Welding of magnesium alloys influence a great effect on magnesium application expansion, especially in marine and aerospace where large-size, complex components are required. Due to specific physical properties of magnesium, its welding requires great control. In general, the solid-state nature of friction stir welding (FSW) process has been found to produce a low concentration of defects. Mechanical properties of  friction stir welded joints are decreases than base material, so to enhance the mechanical properties of welded portion, In the present research additional SiC particulates were incorporated in the weld interface of friction stir welding of Magnesium alloy AZ31B. Silicon Carbide has been added as reinforcement by creating separate geometry, at the edges where the welding is interface with 4 different volume proportions such as 10%, 15%, 25% and 30%. Tool Steel of H13 grade has been used as friction stir welding tool. Rotational Speed of 1400 RPM and Transverse Speed of 25 mm/min were selected. Joined Mg Alloy AZ31B alloy plates were evaluated for their mechanical properties under two different conditions, i.e in the un-reinforced welded condition and reinforced welded conditions. The results of the study revealed that the mechanical properties of the SiC particulates added Mg alloy AZ31B welded joints are superior in all four proportions of SiC, compared to un-reinforced Mg alloy AZ31B welded joints. Microstructural examination of the welded joints was conducted using Optical microscope and revealed that distribution of SiC particles producing increased weld strength. The comparison of the microstructures and mechanical properties of unreinforced Friction stir welded AZ31 with those of SiC reinforced FS-welded joints showed that the addition of SiC particles decreased the grain size and increased the strength.</em></p></div>

Effect of Process Parameters on Mechanical Characterization of Dissimilar Friction Stir Welded Aluminium Alloys

2015 ◽  
Vol 766-767 ◽  
pp. 701-704
Author(s):  
R. Ramesh ◽  
S. Suresh Kumar ◽  
R.V. Srinivasan
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Aluminum Alloy ◽  
Process Parameters ◽  
Weight Ratio ◽  
Welding Parameters ◽  
Friction Stir ◽  
Tool Pin Profile ◽  
Axial Forces ◽  
Tool Pin

Aluminum alloys exhibit poor weldability by conventional fusion welding process. The heat treatable aluminum alloy AA2014 is extensively used in the aircraft industry because it has good ductility and high strength to weight ratio. In this paper the effects of welding parameters and tool profile on the mechanical properties of friction stir welded butt joints of dissimilar aluminum alloy sheets AA6082 and AA2014. The process parameters such as rotational speed, transverse speed and axial forces were considered. The effect of parameters on weld quality was analyzed. Hardness and tensile tests are carried out at room temperature to examine the mechanical properties of the welded joints. The joints produced with straight square tool pin profile have higher ultimate tensile strength, whereas the straight cylindrical tool pin profile results in lower tensile strength.

Semi-Solid Moulding of AZ91D Magnesium Alloy

2016 ◽  
Vol 850 ◽  
pp. 790-801
Author(s):  
Hong Xu ◽  
Xin Zhang ◽  
Chang Shun Wang ◽  
Jin Chuan Hu ◽  
Cheng Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Solid State ◽  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Metal Forming ◽  
Forming Process ◽  
Microstructural Characteristics ◽  
Az91d Magnesium Alloy ◽  
Key Points ◽  
Semi Solid

AZ91D magnesium alloy is one of the most widely used magnesium alloys in the production of metal forming, which use the characteristics from liquid state to solid state of metal to form. The present status of the research and application of the semi-solid forming for AZ91D magnesium alloys at present was reviewed in this paper, including the microstructural characteristics, the thixotropic and rheological behavior, the forming process of semi-solid for AZ91D magnesium alloys and the mechanical properties of the parts made of semi-solid magnesium alloys. The developing prospects and the key points of the semi-solid forming for AZ91D magnesium alloys were forecasted, and the industrial application of the alloy were also discussed.

Evaluation of Corrosion Protection of Sol-Gel Coatings on AZ31B Magnesium Alloy

2008 ◽  
Vol 587-588 ◽  
pp. 390-394 ◽  
Author(s):  
Alexandre Ferreira Galio ◽  
Sviatlana V. Lamaka ◽  
Mikhail L. Zheludkevich ◽  
L.F. Dick ◽  
Iduvirges Lourdes Müller ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Corrosion Protection ◽  
Electrochemical Impedance ◽  
Sol Gel ◽  
Weight Ratio ◽  
Hybrid Coatings ◽  
Magnesium Alloy Az31b ◽  
Excellent Adhesion ◽  
Sol Gel Films

Magnesium is one of the lightest metals and magnesium alloys have good strength to weight ratio making them very attractive for many particular applications [1]. The main drawback of magnesium alloys is their high corrosion susceptibility. Improving the corrosion protection by deposition of thin hybrid films can expand the areas of applications of relatively cheap magnesium alloys. This work aims at investigation of new anticorrosion coating systems for magnesium alloy AZ31B using hybrid sol-gel films. The sol-gels were prepared by copolymerization of 3- glycidoxypropyltrimethoxysilane (GPTMS), titanium alcoxides and special additives which provide corrosion protection of magnesium alloy. Different compositions of sol-gel systems show enhanced long-term corrosion protection of magnesium alloy. The sol-gel coatings exhibit excellent adhesion to the substrate and protect against the corrosion attack. Corrosion behavior of AZ31B substrates pre-treated with sol–gel derived hybrid coatings was tested by Electrochemical Impedance Spectroscopy (EIS). The morphology and the structure of sol-gel films under study were characterized with SEM/EDS techniques.

Surface Modification of Pure Magnesium and Magnesium Alloy AZ91 by Friction Stir Processing

2015 ◽  
Vol 651-653 ◽  
pp. 796-801 ◽  
Author(s):  
Andreas Hütter ◽  
Wilfried Huemer ◽  
Claudia Ramskogler ◽  
Fernando Warchomicka ◽  
Aymen Lachehab ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Friction Stir Processing ◽  
Phase Distribution ◽  
Intermetallic Phases ◽  
Friction Stir ◽  
Alloy Az91 ◽  
Magnesium Alloy Az91

In recent years an interest in magnesium and magnesium alloys not only for the automotive industry but also for medical applications was increasing due to the low density and good specific strength. Magnesium alloys show good castability but lower ductility and strength than wrought materials. For this reason, refinement of grains and homogenous distribution of intermetallic phases are needed to improve formability and mechanical properties. On the other hand, the degradation of the material by corrosion is influenced by the grain size and phase distribution. This work investigates the microstructure evolution of pure Mg and magnesium alloy AZ91 by friction stir processing (FSP) technique. FSP experiments are carried out by constant force, optimizing the rotation and feed rate to obtain a homogenous microstructure, free of defects stir zone, good surface finishing and stable conditions during the process. The results show that the grain size is affected by the spindle speed. Increasing the number of passes reduces also the size of the grains and the intermetallic phases in the AZ91 alloy. The overlapping of passes between overlapping ratio 0.5 to 1 determines an uniform depth of the stir zone over a larger surface area.Hardness measurements are performed to evaluate the influence of FSP parameters on the mechanical properties. The degradation rate of the studied FSP Mg alloys is determined by hydrogen evolution in corrosion immersion tests, which depend strongly on the phase distribution and grain size.

Study on Partial Remelting Microstructures and Mechanical Properties of ZK60-RE Magnesium Alloy

2006 ◽  
Vol 116-117 ◽  
pp. 279-283
Author(s):  
Wei Wei Shan ◽  
Zhi Ming Du ◽  
Shou Jing Luo
Keyword(s):  
Mechanical Properties ◽  
Solid State ◽  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Equal Channel Angular Extrusion ◽  
High Strength ◽  
High Quality ◽  
Partial Remelting ◽  
Semi Solid ◽  
Re Elements

ZK60-RE is a kind of high strength magnesium alloy. Here, starting materials are casting ZK60-RE magnesium alloy and ZK60-RE magnesium alloy extruded by equal channel angular extrusion (ECAE), reheating to semi-solid state and studied on their partial remelting microstructures by means of microscope. The results show that ZK60-RE magnesium alloy extruded by ECAE are much finer and lead to the formation of spheroids quite rapidly while RE elements modified casting need a little longer time. At the same time, the mechanical properties of two kinds of ZK60-RE magnesium alloys are given. To do that, we want to find better magnesium alloys with high mechanical properties and good thixotropy, which adapt to semi-solid process to form the high quality complex component one time.

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