Friction Stir Welding(FSW)is considered to be the most significant development in metal joining in last two decades.FSW has many advantages when welding magnesium or lightweight alloys.The Friction stir welding of mag...Friction Stir Welding(FSW)is considered to be the most significant development in metal joining in last two decades.FSW has many advantages when welding magnesium or lightweight alloys.The Friction stir welding of magnesium alloy has many potential applications in major industries i.e.land transportation,aerospace,railway,shipbuilding and marine,construction,and many other industrial applications.Even magnesium alloys have been used in industrial equipment of nuclear energy as magnesium alloys have low tendency to absorb neutrons,sufficient resistance to carbon dioxide and excellent thermal conductivity.Recently,the research and development in FSW field and associated technologies have been developing rapidly worldwide.In this review article,the basic principle of friction stir welding and several aspects of friction stir welded magnesium alloys have been described.The current state of friction stir welding of magnesium alloys is summarized.In spite of this,much remains to be learned about the process and opportunities for further research are identified.展开更多
Increasing global demands for energy conservation and environmental protection led to the replacement of heavy components with lighter alloys.As magnesium alloys are believed to be unique candidates for lightweight ap...Increasing global demands for energy conservation and environmental protection led to the replacement of heavy components with lighter alloys.As magnesium alloys are believed to be unique candidates for lightweight applications and friction stir welding(FSW)is capable of joining magnesium alloys,in the current work,FSW joint of AZ61 Mg alloy has been fabricated.Microstructure and mechanical properties of the joints were evaluated.The elongated grains of the base metal were recrystallized in the stir zone and in transition zone during friction stir welding.The formation of finer grains in the stir zone of the joint is responsible for increase the hardness of the stir zone.The microhardness of base metal is higher than that of thermo-mechanically affected zone but lower than that of stir zone.The tensile strength of the weld was about 82%of the as-received base metal.The joint failed in ductile mode.This ductile failure of joint was due to the uniform deformation of material.展开更多
The ever-increasing demand for light weighted hard materials for transportation industries encouraged researchers to develop composites with excellent mechanical properties which can transform it into more economical ...The ever-increasing demand for light weighted hard materials for transportation industries encouraged researchers to develop composites with excellent mechanical properties which can transform it into more economical and eco-friendly.Reinforcing the metals with carbonaceous nanomaterials are progressively in focus due to their excellent capability to inculcate and tailor the properties of MMCs.In the present research,a hybrid nanocomposite of MWCNT-Graphene-AZ31 Mg alloy has been developed by using variable tool rotation speeds with friction stir processing(FSP).Optimized reinforcement ratio of 1.6%vol.MWCNT and 0.3%vol.of graphene have been used with variable tool rotation speeds,whereas other processing parameters are kept constant.The developed specimens were investigated using standard testing equipment for evaluating and comparing the mechanical properties on the basis of the microstructure of the processing regions and their morphological analysis,according to the ASTM standards.The obtained results revealed an improvement of 19.72%in microhardness and 77.5% of compressive strength in comparison with the base metal AZ 31 Magnesium alloy,with a tool rotational speed of 1400rpm.The values of tensile stress and percentage area reduction were recorded as less than that of the base metal matrix,but an increasing trend has been observed in the values of both with the improvement on rotational speeds of the tool.The effectual strengthening mechanisms are analyzed on the bases of SEM images and observed that discussed and found that grain refinement strengthening is the major contributor to the strength of the nanocomposite.展开更多
In this investigation,the effects of pin geometry and number of passes on macrostructure,microstructure,wear rate and also microhardness profile of 6061-T6 aluminum alloy surface composites fabricated via friction sti...In this investigation,the effects of pin geometry and number of passes on macrostructure,microstructure,wear rate and also microhardness profile of 6061-T6 aluminum alloy surface composites fabricated via friction stir processing(FSP)were discussed by reinforcement particles of silicon carbide(SiC).The results show that after each FSP pass,a modify distribution of SiC particles is acquired and the increase in the number of passes reduces the average grain size in stir zone(SZ).Furthermore,it is discovered that pin geometry and pass number play a dominant role in the grain size of SZ and distribution of SiC particles in SZ.It is found that after each FSP pass,wear rate is improved due to the uniform distribution of SiC particles in surface of Al/SiC composite.Additionally,the results show that the square pin and smooth(straight)cylindrical pin have the highest and lowest resistance to wear,respectively.展开更多
文摘Friction Stir Welding(FSW)is considered to be the most significant development in metal joining in last two decades.FSW has many advantages when welding magnesium or lightweight alloys.The Friction stir welding of magnesium alloy has many potential applications in major industries i.e.land transportation,aerospace,railway,shipbuilding and marine,construction,and many other industrial applications.Even magnesium alloys have been used in industrial equipment of nuclear energy as magnesium alloys have low tendency to absorb neutrons,sufficient resistance to carbon dioxide and excellent thermal conductivity.Recently,the research and development in FSW field and associated technologies have been developing rapidly worldwide.In this review article,the basic principle of friction stir welding and several aspects of friction stir welded magnesium alloys have been described.The current state of friction stir welding of magnesium alloys is summarized.In spite of this,much remains to be learned about the process and opportunities for further research are identified.
文摘Increasing global demands for energy conservation and environmental protection led to the replacement of heavy components with lighter alloys.As magnesium alloys are believed to be unique candidates for lightweight applications and friction stir welding(FSW)is capable of joining magnesium alloys,in the current work,FSW joint of AZ61 Mg alloy has been fabricated.Microstructure and mechanical properties of the joints were evaluated.The elongated grains of the base metal were recrystallized in the stir zone and in transition zone during friction stir welding.The formation of finer grains in the stir zone of the joint is responsible for increase the hardness of the stir zone.The microhardness of base metal is higher than that of thermo-mechanically affected zone but lower than that of stir zone.The tensile strength of the weld was about 82%of the as-received base metal.The joint failed in ductile mode.This ductile failure of joint was due to the uniform deformation of material.
文摘The ever-increasing demand for light weighted hard materials for transportation industries encouraged researchers to develop composites with excellent mechanical properties which can transform it into more economical and eco-friendly.Reinforcing the metals with carbonaceous nanomaterials are progressively in focus due to their excellent capability to inculcate and tailor the properties of MMCs.In the present research,a hybrid nanocomposite of MWCNT-Graphene-AZ31 Mg alloy has been developed by using variable tool rotation speeds with friction stir processing(FSP).Optimized reinforcement ratio of 1.6%vol.MWCNT and 0.3%vol.of graphene have been used with variable tool rotation speeds,whereas other processing parameters are kept constant.The developed specimens were investigated using standard testing equipment for evaluating and comparing the mechanical properties on the basis of the microstructure of the processing regions and their morphological analysis,according to the ASTM standards.The obtained results revealed an improvement of 19.72%in microhardness and 77.5% of compressive strength in comparison with the base metal AZ 31 Magnesium alloy,with a tool rotational speed of 1400rpm.The values of tensile stress and percentage area reduction were recorded as less than that of the base metal matrix,but an increasing trend has been observed in the values of both with the improvement on rotational speeds of the tool.The effectual strengthening mechanisms are analyzed on the bases of SEM images and observed that discussed and found that grain refinement strengthening is the major contributor to the strength of the nanocomposite.
文摘In this investigation,the effects of pin geometry and number of passes on macrostructure,microstructure,wear rate and also microhardness profile of 6061-T6 aluminum alloy surface composites fabricated via friction stir processing(FSP)were discussed by reinforcement particles of silicon carbide(SiC).The results show that after each FSP pass,a modify distribution of SiC particles is acquired and the increase in the number of passes reduces the average grain size in stir zone(SZ).Furthermore,it is discovered that pin geometry and pass number play a dominant role in the grain size of SZ and distribution of SiC particles in SZ.It is found that after each FSP pass,wear rate is improved due to the uniform distribution of SiC particles in surface of Al/SiC composite.Additionally,the results show that the square pin and smooth(straight)cylindrical pin have the highest and lowest resistance to wear,respectively.
