Texture evolution and wear properties of a frictionally stir processed magnesium matrix composite reinforced by micro graphite and nano graphene particles
Abstrakt
The effect of micro-graphite and nano-graphene particles on the crystallographic texture and wear properties of a magnesium matrix composite is thoroughly examined during friction stir processing. Micro-texture characterizations after the first pass just indicated the formation of common basal deformation textures with the basal planes of most grains vertical to the processing direction.
While, deforming the composites up to three passes resulted in totally different textures for both composites. It is found out that the macro particles can give rise to a random texture with a decreased texture intensity, whereas the nanoparticles surprisingly strengthen the texture and create a strong fiber texture.
Furthermore, it is realized although nanoparticles adversely affect the crystallographic texture after the third pass, they can noticeably improve wear properties through their uniform distribution and excellent self-lubricant properties. It is indicated that friction coefficients for micro-graphite and nano-graphene composites decreased from 0.49 after the first pass (for both composites) to 0.40 and 0.25 after the third deformation pass, respectively.