Superplastic Behavior and Microstructure of Titanium (Ti-6Al-4V) Friction Stir Welds Made under a Variety of Processing Conditions

2010 ◽  
Vol 433 ◽  
pp. 169-176 ◽  
Author(s):  
Paul Edwards ◽  
Mamidala Ramulu ◽  
Daniel G. Sanders
Keyword(s):  
Friction Stir Welding ◽  
Base Material ◽  
Superplastic Forming ◽  
Spindle Speed ◽  
Processing Conditions ◽  
Superplastic Behavior ◽  
Friction Stir ◽  
Fine Grained ◽  
Weld Parameters

Friction Stir Welding of Ti-6Al-4V was performed on 5 mm thickness plate in order to assess the affect of welding conditions on the resulting microstructure and superplastic forming behavior of the joints. A variety of welding conditions were tested and all welds were subsequently Superplastically formed. It was found that the weld parameters do influence the microstructure and degree of superplastic performance of the joints. Spindle speed was found to have the most dominant affect on the resulting microstructure and superplastic forming behavior. Low spindle speed welds lead to fine grained microstructures and highly superplastic welds, relative to the base material, while high spindle speed welds larger grained microstructures and less superplastic welds.

Identification of Process Parameters for Friction Stir Welding Ti–6Al–4V

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
P. Edwards ◽  
M. Ramulu
Keyword(s):  
Friction Stir Welding ◽  
Feed Rate ◽  
Void Formation ◽  
Base Material ◽  
Spindle Speed ◽  
Fatigue Properties ◽  
Process Window ◽  
Welding Parameters ◽  
Friction Stir ◽  
Weld Parameters

An experimental study was conducted to identify acceptable welding parameters for friction stir welding Ti-6Al-4V butt joints, ranging from 3 mm to 12 mm in thickness. The primary parameters of interest were the spindle speed and feed rate. Welds were produced using spindle speeds of 140–320 rpm and feed rates between 40 mm/min and 125 mm/min. Joints were evaluated by macro- and micrometallurgical examination along with limited fatigue and tensile testing. The weld parameters were found to influence the microstructure, penetration, void formation, and tool wear among other things. A process window was identified for combinations of the feed rate and spindle speed capable of achieving defect free joints for a given tooling configuration and thickness. It was found that the tensile and fatigue properties of the welds produced in this study were comparable to Ti–6Al–4V base material properties.

Optimization of the Friction Stir Welding Process for Superplastic Forming and Improved Surface Texture for Titanium Aerospace Structures

2010 ◽  
Vol 433 ◽  
pp. 153-167 ◽  
Author(s):  
Daniel G. Sanders ◽  
Paul Edwards ◽  
Mamidala Ramulu ◽  
Glenn Grant
Keyword(s):  
Friction Stir Welding ◽  
Surface Texture ◽  
Feed Rate ◽  
Welding Process ◽  
Superplastic Forming ◽  
Spindle Speed ◽  
Process Conditions ◽  
Parent Metal ◽  
Friction Stir ◽  
Fine Grain

In friction stir welding (FSW), the semi-circular shaped FSW pin tool feed marks that are left behind varied in depth and shape which are detrimental not only in fatigue performance but also in further processing such as superplastic forming (SPF). Experimental investigation was conducted to determine the effects of changes to the FSW process parameters on the surface roughness of the weld of fine grain 2 mm thick titanium alloy, Ti- 6Al-4V. In addition to optimizing the surface texture of the welds, the superplastic performance of the weld nugget was made to be equal to the superplasticity of the parent metal by altering the spindle speed and feed rate used during FSW to identify the quality in terms of cold weld or hot weld. FSW process conditions of spindle speed of 500 RPM and a feed rate of 150 mm/min was found to produce a uniform deformation in both weld and parent metal when the joint was superplastc formed.

The Use of Extruded Profiles as Filling Material in Friction Stir Welding (FSW)

2009 ◽  
Vol 424 ◽  
pp. 137-144
Author(s):  
Lorenzo Donati ◽  
Luca Tomesani
Keyword(s):  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Process Parameters ◽  
Base Material ◽  
Tensile Tests ◽  
Filling Material ◽  
Processing Conditions ◽  
Friction Stir ◽  
Optimal Processing ◽  
Extrude Profile

In this paper, an innovative approach is presented for joining two sheets with an extruded profile all made by AA6082-T6 aluminum alloy. The tested configuration is the T-joint and the innovation presented in this paper is the use of a specially design appendix of the extruded profile as filler material during the friction welding. In particular three configurations were analyzed: without appendix, with I appendix and with T appendix. In the experiments, several process parameters and PIN shapes were investigated in order to determine optimal processing conditions able to produce an effective sound weld. Specimens were extracted from the joint and tensile tests were performed along the sheet direction thus allowing a comparison of the welded sections respect to the base material. It was found that the appendixes of the extrude profile are able to effectively fill the distance between the sheets and, in particular with the T shape, a gap up to 1,7 mm on the retreating side was successfully welded.

scholarly journals Influence of Mx-Trivex, A-Skew, Three Flat Threaded and Concave Shouldered Mx-Triflute Tool Pin Profiles on Tensile Properties and Fractural Behaviour of Aa 6082-T6 Weldments During Friction Stir Welding

2020 ◽  
Vol 9 (4) ◽  
pp. 1376-1384
Keyword(s):  
Friction Stir Welding ◽  
Tensile Test ◽  
Weld Zone ◽  
Base Material ◽  
Traverse Speed ◽  
Friction Stir ◽  
Tool Pin ◽  
Solid State Joining ◽  
Joining Process ◽  
Brass Wire

Friction Stir Welding (FSW) is a topical and propitious solid-state joining process producing economical and strengthened joints of age-hardened and heat-treatable Aluminium Alloy AA 6082-T6. Mechanical and fractural behaviour of weldments were investigated in order to find crack initiation and necking on the weld zone thereby perceiving the complete behaviour of fracture occurred near the weld zone. Weldments are fabricated by employing four tool pin profiles namely MX-TRIVEX, A-SKEW, Three flat threaded and Concave shouldered MX-TRIFLUTE tools at various rotational speeds 1000 rpm, 1200 rpm and 1400 rpm at single traverse speed 25 mm/min. EXCETEX-EX-40 CNC wire cut EDM with 0.25 mm brass wire diameter has been employed to perform the extraction of tensile test specimens from the weldments according to ASTM E8M-04 standard. Tensile test was performed on elctromechanically servo controlled TUE-C-200 (UTM machine) according to ASTM B557-16 standards Maximum Ultimate Tensile Strength (UTS) of 172.33 MPa (55.5% of base material) and 0.2% Yield Stress (YS) of 134.10 MPa (51.5% of base material) were obtained by using A-SKEW at 1400 rpm, 25 mm/min and maximum % Elongation (%El) of 11.33 (113.3% of base material) was obtained at MX-TRIVEX at 1000 rpm, 25 mm/min. Minimum UTS of 131.16 MPa (42.30% of base material) and 0.2% YS of 105.207 MPa (40.46% of base material )were obtained by using Concave shouldered MX-TRIFLUTE at 1400 rpm, 25 mm/min. Minimum % El of 5.42 ( 54.2% of base material) was obtained by using A-SKEW at 1000 rpm, 25 mm/min.

Multiaxial Mechanical Strength of AA-2024-T3 Aluminium Alloy Sheets Joined by Friction Stir Welding Processes

2009 ◽  
Vol 83-86 ◽  
pp. 1243-1250 ◽  
Author(s):  
R.L.L.P. Cerveira ◽  
G. F. Batalha
Keyword(s):  
Friction Stir Welding ◽  
Base Material ◽  
Short Review ◽  
Multiaxial Loading ◽  
Angle Variation ◽  
Friction Stir ◽  
Aa 2024 ◽  
Aeronautical Industry ◽  
Welding Processes ◽  
Joining Process

The aim is to analyze a junction produced by a Friction Stir Welding (FSW) joining process under multiaxial loading, employing a modified Arcan test that allows an angle variation of the loading in order to evaluate the failure of the FSW weldment as compared to the base material. A short review of the earlier studies and relevant theories about the FSW processes and fracture modes I and II under multiaxial loading are presented and were experimentally evaluated for an AA2024-T3 aluminum alloy sheets (t = 1.6 mm) processed by FSW. The results obtained can serve as a basis to compare the junctions made using FSW and conventional joint methods such as rivets (very common practice in the aeronautical industry).

Microhardness and Microstructural Studies on Underwater Friction Stir Welding of 5052 Aluminum Alloy

2017 ◽  
Author(s):  
Srinivasa Rao Pedapati ◽  
Dhanis Paramaguru ◽  
Mokhtar Awang
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Plate Thickness ◽  
Base Material ◽  
Friction Stir ◽  
Underwater Friction Stir Welding ◽  
Void Area ◽  
Average Size ◽  
Microstructural Studies

As compared to normal Friction Stir Welding (FSW) joints, the Underwater Friction Stir Welding (UFSW) has been reported to be obtainable in consideration of enhancement in mechanical properties. A 5052-Aluminum Alloy welded joints using UFSW method with plate thickness of 6 mm were investigated, in turn to interpret the fundamental justification for enhancement in mechanical properties of material through UFSW. Differences in microstructural features and mechanical properties of the joints were examined and discussed in detail. The results indicate that underwater FSW has reported lower hardness value in the HAZ and higher hardness value in the intermediate of stir zone (SZ). The average hardness value of underwater FSW increases about 53% greater than its base material (BM), while 21% greater than the normal FSW. The maximum micro-hardness value was three times greater than its base material (BM), and the mechanical properties of underwater FSW joint is increased compared to the normal FSW joint. Besides, the evaluated void-area fraction division in the SZ of underwater FSW joint was reduced and about one-third of the base material (BM). The approximately estimated average size of the voids in SZ of underwater FSW also was reduced to as low as 0.00073 mm2, when compared to normal FSW and BM with approximately estimated average voids size of 0.0024 mm2 and 0.0039 mm2, simultaneously.

Study on Forming Behaviour of Friction Stir Welded Blanks During Single Point Incremental Forming (SPIF) Process

2020 ◽  
Author(s):  
Shalin Marathe ◽  
Harit Raval
Keyword(s):  
Friction Stir Welding ◽  
Incremental Forming ◽  
Single Point ◽  
Base Material ◽  
Forming Limit ◽  
Single Point Incremental Forming ◽  
Cnc Milling ◽  
Forming Process ◽  
Friction Stir ◽  
Welding Processes

Abstract The automobile, transportation and shipbuilding industries are aiming at fuel efficient products. In order to enhance the fuel efficiency, the overall weight of the product should be brought down. This requirement has increased the use of material like aluminium and its alloys. But, it is difficult to weld aluminium using conventional welding processes. This problem can be solved by inventions like friction stir welding (FSW) process. During fabrication of product, FSW joints are subjected to many different processes and forming is one of them. During conventional forming, the formability of the welded blanks is found to be lower than the formability of the parent blank involved in it. One of the major reasons for reduction in formability is the global deformation provided on the blank during forming process. In order to improve the formability of homogeneous blanks, Single Point Incremental Forming (SPIF) is found to be giving excellent results. So, in this work formability of the welded blanks is investigated during the SPIF process. Friction Stir Welding is used to fabricate the welded blanks using AA 6061 T6 as base material. Welded blanks are formed in to truncated cone through SPIF process. CNC milling machine is used as SPIF machine tool to perform the experimental work. In order to avoid direct contact between weld seam and forming tool, a dummy sheet was used between them. As responses forming limit curve (FLC), surface roughness, and thinning are investigated. It was found that use of dummy sheet leads to improve the surface finish of the formed blank. The formability of the blank was found less in comparison to the parent metal involved in it. Uneven distribution of mechanical properties in the welded blanks leads to decrease the formability of the welded blanks.

Effect of weld parameters on joint quality in friction stir welding of Mg alloy to DP steel dissimilar materials

2021 ◽  
Vol 35 ◽  
pp. 502-516
Author(s):  
Suryakanta Sahu ◽  
Omkar Mypati ◽  
Surjya K. Pal ◽  
Mahadev Shome ◽  
Prakash Srirangam
Keyword(s):  
Friction Stir Welding ◽  
Dissimilar Materials ◽  
Mg Alloy ◽  
Dp Steel ◽  
Friction Stir ◽  
Weld Parameters ◽  
Joint Quality

scholarly journals Research on the Friction Stir Welding of Sc-Modified AA2519 Extrusion

Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1024 ◽  
Author(s):  
Robert Kosturek ◽  
Lucjan Śnieżek ◽  
Janusz Torzewski ◽  
Marcin Wachowski
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Base Material ◽  
Stir Zone ◽  
Welding Parameters ◽  
Friction Stir ◽  
Treated Condition ◽  
Heat Treated ◽  
Heat Treated Condition ◽  
Fsw Parameters

The aim of this research was to investigate the effect of friction stir welding (FSW) parameters on microstructure and mechanical properties of Sc-modified AA2519 extrusion joints. The workpiece was welded by FSW in non-heat-treated condition with seven different sets of welding parameters. For each obtained joint macrostructure and microstructure observations were performed. Mechanical properties of joints were investigated using tensile test together with localization of fracture location. Joint efficiencies were established by comparing measured joints tensile strength to the value for base material. The obtained results show that investigated FSW joints of Sc-modified AA2519 in the non-heat-treated condition have joint efficiency within the range 87–95%. In the joints obtained with the lowest ratio of the tool rotation speed to the tool traverse speed, the occurrence of imperfections (voids) localized in the stir zone was reported. Three selected samples were subjected to further investigations consisting microhardness distribution and scanning electron microscopy fractography analysis. As the result of dynamic recrystallization, the microhardness of the base material value of 86 HV0.1 increased to about 110–125 HV0.1 in the stir zone depending on the used welding parameters. Due to lack of the strengthening phase and low strain hardening of used alloy the lack of a significantly softened zone was reported by both microhardness analysis and investigation of the fractured samples.

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