Composite layers containing~0.8%vol Al_(2)O_(3) nanoparticles were produced on AZ91 magnesium alloy by friction stir processing(FSP).The treated layers were characterized using optical and scanning electron microscope...Composite layers containing~0.8%vol Al_(2)O_(3) nanoparticles were produced on AZ91 magnesium alloy by friction stir processing(FSP).The treated layers were characterized using optical and scanning electron microscopes,as well as microhardness and wear testing units.It was noticed that,by reducing the rotational speed and increasing the travel speed,the grain size of the treated layer reduces and its hardness increases.In addition,the presence of nano Al_(2)O_(3) reduces the grain sizes of the layers further and increases their hardness.Furthermore,FSP of AZ91 with Al_(2)O_(3) particles improved the wear resistance significantly and changed the wear mechanism from oxidation and adhesive mode in the as-received AZ91 to oxidation and abrasive in the FSPed specimens.Finally,the rotational speed of 800 rpm and the travel speed of 40 mm/min were the optimum parameters for achieving a suitable composite layer with the highest hardness and wear resistance among the treated layers.展开更多
Taguchi experimental design technique was applied to determine the most influential controlling parameters of FSP such as tool rotational speed,travel speed,tilt angle and penetration depth on hardness value of Mg.In ...Taguchi experimental design technique was applied to determine the most influential controlling parameters of FSP such as tool rotational speed,travel speed,tilt angle and penetration depth on hardness value of Mg.In this case,9 combinations of these 4 essential processing parameters were set and Taguchi's method followed exactly.Signal to noise ratio(S/N)analysis showed that maximum hardness achieved when rotational and travel speeds,penetration depth and tilt angel were chosen as 1600 rpm,63 mm/min,0.1 mm and 2°,respectively.In addition,analysis of variance(ANOVA)technique indicated that tilt angle and rotational as well as travel speed are the significant influential parameters in the hardness value of the treated samples,respectively.Finally a model for hardness values based on FSP parameters was calculated by design expert which was also confirmed by experimental results.展开更多
文摘Composite layers containing~0.8%vol Al_(2)O_(3) nanoparticles were produced on AZ91 magnesium alloy by friction stir processing(FSP).The treated layers were characterized using optical and scanning electron microscopes,as well as microhardness and wear testing units.It was noticed that,by reducing the rotational speed and increasing the travel speed,the grain size of the treated layer reduces and its hardness increases.In addition,the presence of nano Al_(2)O_(3) reduces the grain sizes of the layers further and increases their hardness.Furthermore,FSP of AZ91 with Al_(2)O_(3) particles improved the wear resistance significantly and changed the wear mechanism from oxidation and adhesive mode in the as-received AZ91 to oxidation and abrasive in the FSPed specimens.Finally,the rotational speed of 800 rpm and the travel speed of 40 mm/min were the optimum parameters for achieving a suitable composite layer with the highest hardness and wear resistance among the treated layers.
文摘Taguchi experimental design technique was applied to determine the most influential controlling parameters of FSP such as tool rotational speed,travel speed,tilt angle and penetration depth on hardness value of Mg.In this case,9 combinations of these 4 essential processing parameters were set and Taguchi's method followed exactly.Signal to noise ratio(S/N)analysis showed that maximum hardness achieved when rotational and travel speeds,penetration depth and tilt angel were chosen as 1600 rpm,63 mm/min,0.1 mm and 2°,respectively.In addition,analysis of variance(ANOVA)technique indicated that tilt angle and rotational as well as travel speed are the significant influential parameters in the hardness value of the treated samples,respectively.Finally a model for hardness values based on FSP parameters was calculated by design expert which was also confirmed by experimental results.
