scholarly journals Investigation of mechanical and micro structural properties of ST14 steel sheet joints by friction stir welding process

2020 ◽  
Author(s):  
Mahmoud Afshari ◽  
Hossein Norozi Foroushani ◽  
Ehsan Salahshour Rad ◽  
Iraj Sattari Far ◽  
Amirhossein Alavi
Keyword(s):  
Friction Stir Welding ◽  
Tungsten Carbide ◽  
Rotational Speed ◽  
Welding Process ◽  
High Strength ◽  
Hardness Test ◽  
Linear Speed ◽  
Friction Stir ◽  
St14 Steel ◽  
Carbide Particles

Abstract High strength and ductility are considered as the superior features of ST14 steel, which have resulted in the extensive usage of this material in the automotive and aerospace industries. Friction stir welding (FSW) is one of the new methods of solid-state welding with preferable mechanical properties for joining steel components. In this study, the mechanical and microstructural properties of 1.5 mm thick ST14 steel sheets in FSW process are investigated. The results revealed the highest tensile strength of 305 MPa for the welded specimen at the rotational speed of 800 rpm and linear speed of 80 mm/min. In addition, higher separation rate of the tungsten carbide particles from the tool as a result of higher heat input to the piece was realized from the metallographic test with the use of sample with rotational speed of 1000 rpm and linear speed of 50 mm/min. Moreover, regarding the results of micro hardness test, an increased hardness to 115\(\pm\)1 HV in the stirred zone (SZ) was acquired in this sample. Furthermore, the presence of the tungsten carbide particles were observed in this area.

scholarly journals Investigation of mechanical and micro structural properties of ST14 steel sheet joints by friction stir welding process

2020 ◽  
Author(s):  
Mahmoud Afshari ◽  
Hossein Norozi Foroushani ◽  
Ehsan Salahshour Rad ◽  
Iraj Sattari Far ◽  
Amirhossein Alavi
Keyword(s):  
Friction Stir Welding ◽  
Tungsten Carbide ◽  
Rotational Speed ◽  
Welding Process ◽  
High Strength ◽  
Hardness Test ◽  
Linear Speed ◽  
Friction Stir ◽  
St14 Steel ◽  
Carbide Particles

Abstract High strength and ductility are considered as the superior features of ST14 steel, which have resulted in the extensive usage of this material in the automotive and aerospace industries. Friction stir welding (FSW) is one of the new methods of solid-state welding with preferable mechanical properties for joining steel components.In this study, the mechanical and microstructural properties of 1.5 mm thick ST14 steel sheets in FSW process are investigated. The results revealed the highest tensile strength of 305 MPa for the welded specimen at the rotational speed of 800 rpm and linear speed of 80 mm/min. In addition, higher separation rate of the tungsten carbide particles from the tool as a result of higher heat input to the piece was realized from the metallographic test with the use of sample with rotational speed of 1000 rpm and linear speed of 50 mm/min. Moreover, regarding the results of micro hardness test, an increased hardness to 115H1 HV in the stirred zone (SZ) was acquired in this sample. Furthermore, the presence of the tungsten carbide particles were observed in this area.

scholarly journals Investigation of mechanical and micro structural properties of ST14 steel sheet joints by friction stir welding process

2020 ◽  
Author(s):  
Mahmoud Afshari ◽  
Ehsan Salahshour Rad ◽  
Hossein Norozi Foroushani ◽  
Iraj Sattari Far
Keyword(s):  
Friction Stir Welding ◽  
Tungsten Carbide ◽  
Rotational Speed ◽  
Welding Process ◽  
Linear Motion ◽  
Friction Stir ◽  
Friction Stir Welding Process ◽  
Motion Speed ◽  
St14 Steel ◽  
Carbide Particles

Abstract High strength and ductility are some of reasons that make ST14 steel one of the most widely used steels in automotive and aerospace industries. FSW is one of the new methods of solid-state welding that is proposed as a method with desirable mechanical properties.In this study, mechanical and microstructural properties of 1.5mm thick ST14 steel sheets were investigated in the friction stir welding process. The results showed that the welded specimen with rotational speed of 800 rpm and linear motion speed of 80 mm/min had the highest tensile strength of 305MPa. In addition, results of metallographic test showed that the sample with 1000 rpm rotational speed and 50 mm/min linear motion speed had the highest heat input to the piece, and therefore the tungsten carbide particles were separated from the instrument and entered the stirred zone. Also the results of micro hardness test showed that in the welded specimen with rotational speed of 1000 rpm and linear motion speed of 50 mm/min, hardness increased to 115H1 HV in the stirred zone, which is higher than hardness of other samples in same region. It can be claimed that tungsten carbide particles are present in this area.

An analytical and experimental investigation considering the effect of material flow velocity on tensile strength of a steel alloy joint produced by friction stir welding process

2020 ◽  
pp. 095440622093631
Author(s):  
Behzad Hadi ◽  
ME Aalami-Aleagha ◽  
Saeed Feli
Keyword(s):  
Friction Stir Welding ◽  
Flow Velocity ◽  
Analytical Method ◽  
Rotational Speed ◽  
Material Flow ◽  
Welding Process ◽  
Linear Speed ◽  
Friction Stir ◽  
Friction Stir Welding Process ◽  
Tool Pin

In this paper, the effects of linear speed, rotational speed, and tool radius of the pin and shoulder are investigated on the material flow velocity in friction stir welds. To obtain the maximum material flow velocity by an analytical method, a suggested relation is introduced for the rotational speed and tool optimum radius. The derived relation is based on the assumption of a velocity field in the stirring region. Besides, the effect of the linear speed on material flow velocity is investigated based on continuity and momentum equations. Finally, by using the experimental method and checking the mechanical properties of the welded parts obtained with different rotational speed, linear speed, and tool dimensions, the proposed analytical model is validated. The results indicate that in the friction stir welding process, the significant component effect on the stirring process is generated through the tool pin radius size. Besides, increasing the material flow velocity in the boundary layer increases the yield and ultimate strength of welds. To achieve the high-quality welds, rotational speed and other tool dimensions must be selected considering the equation extracted from the analytical method. Also, to make the maximum life for the pin and its components in friction stir welding of high melting point metals such as steel alloys, the operation is adjusted at a lower linear speed to prevent the destruction of the tool and improve the quality of the joint.

Study of the Key Issues of Friction Stir Welding of Titanium Alloy

2010 ◽  
Vol 638-642 ◽  
pp. 1185-1190 ◽  
Author(s):  
Hui Jie Liu ◽  
Li Zhou ◽  
Yong Xian Huang ◽  
Qi Wei Liu
Keyword(s):  
Titanium Alloy ◽  
Friction Stir Welding ◽  
Melting Point ◽  
Titanium Alloys ◽  
Welding Process ◽  
High Strength ◽  
Liquid Cooling ◽  
Friction Stir ◽  
Key Issues ◽  
Aluminum And Magnesium Alloys

As a new solid-state welding process, friction stir welding (FSW) has been successfully used for joining low melting point materials such as aluminum and magnesium alloys, but the FSW of high melting point materials such as steels and titanium alloys is still difficult to carry out because of their strict requirements for the FSW tool. Especially for the FSW of titanium alloys, some key technological issues need to solve further. In order to accomplish the FSW of titanium alloys, a specially designed tool system was made. The system was composed of W-Re pin tool, liquid cooling holder and shielding gas shroud. Prior to FSW, the Ti-6Al-4V alloy plates were thermo-hydrogen processed to reduce the deformation resistance and tool wear during the FSW. Based on this, the thermo-hydrogen processed Ti-6Al-4V alloy with different hydrogen content was friction stir welded, and the microstructural characterizations and mechanical properties of the joints were studied. Experimental results showed that the designed tool system can fulfill the requirements of the FSW of titanium alloys, and excellent weld formation and high-strength joint have been obtained from the titanium alloy plates.

On the problem of tool destruction when obtaining fixed joints of thick-walled aluminum alloy blanks by friction welding with mixing

2021 ◽  
Vol 23 (3) ◽  
pp. 72-83
Author(s):  
Kirill Kalashnikov ◽  
◽  
Andrey Chumaevskii ◽  
Tatiana Kalashnikova ◽  
Aleksey Ivanov ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Friction Welding ◽  
Welding Process ◽  
High Strength ◽  
Heterogeneous Structure ◽  
Adhesive Interaction ◽  
Friction Stir ◽  
Tool Shoulder ◽  
Electric Erosion

Introduction. Among the technologies for manufacturing rocket and aircraft bodies, marine vessels, and vehicles, currently, more and more attention is paid to the technology of friction stir welding (FSW). First of all, the use of this technology is necessary where it is required to produce fixed joints of high-strength aluminum alloys. In this case, special attention should be paid to welding thick-walled blanks, as fixed joints with a thickness of 30.0 mm or more are the target products in the rocket-space and aviation industries. At the same time, it is most prone to the formation of defects due to uneven heat distribution throughout the height of the blank. It can lead to a violation of the adhesive interaction between the weld metal and the tool and can even lead to a destruction of the welding tool. The purpose of this work is to reveal regularities of welding tool destruction depending on parameters of friction stir welding process of aluminum alloy AA5056 fixed joints with a thickness of 35.0 mm. Following research methods were used in the work: the obtaining of fixed joints was carried out by friction welding with mixing, the production of samples for research was carried out by electric erosion cutting, the study of samples was carried out using optical metallography methods. Results and discussion. As a result of performed studies, it is revealed that samples of aluminum alloy with a thickness of 35.0 mm have a heterogeneous structure through the height of weld. There are the tool shoulder effect zone and the pin effect zone, in which certain whirling of weld material caused by the presence of grooves on tool surface is distinctly distinguished. It is shown that the zone of shoulders effect is the most exposed to the formation of tunnel-type defects because of low loading force and high welding speeds. It is revealed that tool destruction occurs tangentially to the surface of the tool grooves due to the high tool load and high welding speeds.

Application of Electric Current in Friction Stir Welding

2010 ◽  
Author(s):  
Matthew Pitschman ◽  
Jacob W. Dolecki ◽  
Garret W. Johns ◽  
Jun Zhou ◽  
John T. Roth
Keyword(s):  
Friction Stir Welding ◽  
Electric Current ◽  
Mechanical Energy ◽  
Welding Process ◽  
High Strength ◽  
Work Piece ◽  
Friction Stir ◽  
Weld Metals ◽  
Weld Properties ◽  
Electrically Enhanced

Friction Stir Welding (FSW) is a relatively new joining technique and has many applications. In FSW, heat generated due to friction between FSW tool and work-piece material softens the material and allows the materials in work-pieces to be stirred and joined together. FSW allows the work-pieces to be joined without reaching the melting point of the material, thus resulting in better welds. However, a large amount of mechanical energy has to be consumed for FSW of high-strength, difficult-to-weld metals such as titanium alloys. Hence, new FSW methods should be investigated to reduce the required energy. In this study, an innovative electrically-enhanced friction stir welding (EEFSW) has been developed. Electric current is passed in welding coupons of Aluminum 6061 plates and its effect on welding process and welds are examined. The results indicate that, with the aid of electric current, improvement in welding speed and reduction in energy consumption is obtainable, which enhances the productivity and widens the range of applications of FSW. Weld properties are found to be affected by the introduced current as well.

scholarly journals Experimental Investigation of Friction Stir Welding on 6061-T6 Aluminum Alloy using Taguchi-Based GRA

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1480
Author(s):  
Assefa Asmare ◽  
Raheem Al-Sabur ◽  
Eyob Messele
Keyword(s):  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Process Parameters ◽  
Rotational Speed ◽  
Weight Ratio ◽  
Welding Process ◽  
Quality Criteria ◽  
Alloy Sheet ◽  
Friction Stir ◽  
Weld Joints

The use of aluminum alloys, nowadays, is swiftly growing from the prerequisite of producing higher strength to weight ratio. Lightweight components are crucial interest in most manufacturing sectors, especially in transportation, aviation, maritime, automotive, and others. Traditional available joining methods have an adverse effect on joining these lightweight engineering materials, increasing needs for new environmentally friendly joining methods. Hence, friction stir welding (FSW) is introduced. Friction stir welding is a relatively new welding process that can produce high-quality weld joints with a lightweight and low joining cost with no waste. This paper endeavors to deals with optimizing process parameters for quality criteria on tensile and hardness strengths. Samples were taken from a 5 mm 6061-T6 aluminum alloy sheet with butt joint configuration. Controlled process parameters tool profile, rotational speed and transverse speed were utilized. The process parameters are optimized making use of the combination of Grey relation analysis method and L9 orthogonal array. Mechanical properties of the weld joints are examined through tensile, hardness, and liquid penetrant tests at room temperature. From this research, rotational speed and traverse speed become significant parameters at a 99% confidence interval, and the joint efficiency reached 91.3%.

Influence of Tool Rotational Speed on the Mechanical Properties of Friction Stir Welded Al-Cu-Li Alloy

2016 ◽  
Vol 857 ◽  
pp. 228-231
Author(s):  
Ho Sung Lee ◽  
Ye Rim Lee ◽  
Kyung Ju Min
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Space Shuttle ◽  
Welding Process ◽  
High Strength ◽  
Fusion Welding ◽  
Welding Parameters ◽  
Friction Stir ◽  
Mechanical And Microstructural Properties ◽  
Tool Rotation

Aluminum-Lithium alloys have been found to exhibit superior mechanical properties as compared to the conventional aerospace aluminum alloys in terms of high strength, high modulus, low density, good corrosion resistance and fracture toughness at cryogenic temperatures. Even though they do not form low-melting eutectics during fusion welding, there are still problems like porosity, solidification cracking, and loss of lithium. This is why solid state friction stir welding is important in this alloy. It is known that using Al-Cu-Li alloy and friction stir welding to super lightweight external tank for space shuttle, significant weight reduction has been achieved. The objective of this paper is to investigate the effect of friction stir tool rotation speed on mechanical and microstructural properties of Al-Cu-Li alloy. The plates were joined with friction stir welding process using different tool rotation speeds (300-800 rpm) and welding speeds (120-420 mm/min), which are the two prime welding parameters in this process.

Investigation of Vibration Assisted Friction Stir Welding

2012 ◽  
Vol 504-506 ◽  
pp. 741-746 ◽  
Author(s):  
Hamid Montazerolghaem ◽  
Mohsen Badrossamay ◽  
Alireza Fadaei Tehrani
Keyword(s):  
Friction Stir Welding ◽  
Axial Force ◽  
Process Condition ◽  
Welding Process ◽  
High Strength ◽  
State Spaces ◽  
Friction Stir ◽  
Fsw Simulation ◽  
Resultant Forces ◽  
Welding Force

Friction Stir Welding (FSW) is a relatively new solid state joining method that can be used to achieve very good weld quality. This technique is energy efficient, environment friendly, and versatile. The FSW process utilizes a rotating tool in which includes a pin and shoulder to perform the welding process. FSW applications in high strength alloys, such as stainless steel remain limited due to large welding force and consequent tool wear. It has been shown that applying the ultrasonic vibration on some processes such as turning and drilling the resultant forces are decreased and process condition is improved. In this paper the influence of applying vibration on FSW is investigated in simulating tools. For FSW modeling a proper transfer function of axial force has been proposed. The resultant axial force of conventional FSW and Vibration Assisted FSW (VAFSW) are compared in frequency and time domain state spaces. A good correlation between FSW simulation and experiments is observed. For further investigation of VAFSW the response surface of design of experiment (DOE) method is utilized. The influence of changing VAFSW process parameters is investigated. The simulation results indicate that vibration helps to decrease the welding force. Using DOE method the effects of implemented frequency and vibration speed amplitude in FSW are found.

Sign in / Sign up

Export Citation Format

Share Document