Abstract
The influence of pre- shot peening and welding parameters on mechanical and metallurgical properties of dissimilar and similar aluminum alloys AA2024-T3 and AA6061-T6 joints using friction stir welding have been studied. In this work, numbers of plates were equipped from sheet alloys in dimensions (150*50*6) mm then some of them were exposed to shot peening process before friction stir welding using steel ball having diameter 1.25 mm for period of 15 minutes. FSW joints were manufactured from plates at three welding speeds (28, 40, 56 mm/min) and welding speed 40mm/min was chosen at a rotating speed of 1400 rpm for welding the dissimilar pre- shot plates. Tow joints were made at rotational speed of 1000 rpm and welding speed of 40m/min from shot and without shot peening plats. Welding temperature was measured in three zones using thermocouple. Micro hardness (HV) and tensile tests were performed to evaluate the mechanical characteristic of the joints. The results show a decay in mechanical qualities when the welding speed was increased and the best result was at (28) mm/min and the opposite result was obtained when rotational speed increased and pre-shot contributed in improving of this decay at 88% of welding speed (40) mm/min and 98% at the rotational speed of 1000 rpm.
 
 
Highlights
The connection of dissimilar materials based on significant engineering uses just "power generation", petrochemical, chemical, Nuclear, aerospace transportation and electronic manufactures, the connection of dissimilar materials gift additional defiance and difficulties than similar by using friction stir welding due to the probability of the realization of "brittle intermetallic phases" and little period of eutectics dissolution [1].Friction stir welding (FSW) is a method in solid stat include embrace the ascent of a spinning hard steel nail broadens by a cylinder-shaped shoulder between two contacting metal plates [2]
Mechanical qualities like tensile strength, ductility, hardness compering with fusion welded joints [5]., structure of weld, due to hard mechanical stresses shows three clear microstructural zones on the transverse cross section of the FSW joint, .these zones are a nugget, or stirred zone, thermo-mechanical affected zone (TMAZ), and a heat affected zone (HAZ),nugget zone NZ is a region through which tool pin passes and experiences both high deformation and heat treatment
The tool dimensions is composed of shoulder of (20mm diameter) and probe of (6mm diameter and 5 mm length ).In this study the rotation speed tool (1400 rpm) was used to get many weld joints at mutable welding speed of (28,40,56 mm/min ) fixed the welding speed for (40mm/min) and the same rotation speed (1400 rpm) to join the shot peening plate which is shown in Fig(2 ) for comparative the result with second parameter the rotation speed was taken(1000)rpm at welding speed (40mm/min) to weld butt joint from shot and without shot plate .Fig.(3,4,5)show the Macrograph weld joint of Specimen (A,B,C) friction stir weld joint
Summary
The connection of dissimilar materials based on significant engineering uses just "power generation", petrochemical, chemical, Nuclear, aerospace transportation and electronic manufactures, the connection of dissimilar materials gift additional defiance and difficulties than similar by using friction stir welding due to the probability of the realization of "brittle intermetallic phases" and little period of eutectics dissolution [1].Friction stir welding (FSW) is a method in solid stat include embrace the ascent of a spinning hard steel nail broadens by a cylinder-shaped shoulder between two contacting metal plates [2]. Mechanical qualities like tensile strength, ductility, hardness compering with fusion welded joints [5]., structure of weld, due to hard mechanical stresses shows three clear microstructural zones on the transverse cross section of the FSW joint, .these zones are a nugget, or stirred zone, thermo-mechanical affected zone (TMAZ), and a heat affected zone (HAZ) ,nugget zone NZ is a region through which tool pin passes and experiences both high deformation and heat treatment It generally consists of very fine equiaxed [6]these change in microstructures cause decay in mechanical characteristic this decay can improve by using one of Mechanical surface treatments such as a cold working process (shot peening) in which small spherical shots the surface of plat produce compressive residual stresses and extremely high dislocation densities near the faces films consequent inhomogeneous plastic deformations[7] The figure of effective factors on the shot-peening method is: type, size and shape of the shots, peening time, torrent speed, air pressure on the peened element, distance from nozzle to material surface (peening distance), nozzle angle, peening intensity and face covering percentage[8]many, researchers studied the subject such as:-. The present study the influence of pre shot peening ,welding speed, rotational speed on mechanical properties for dissimilar aluminum alloys 2024-T3and 6061-T6 friction stir welded joint
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
