Plastic Deformation And Properties Of In-situ Nanoparticle Reinforced ZrB₂/6061 Aluminum Matrix Composites

In this paper,the in-situ nano-ZrB₂ particle reinforced 6061 aluminum matrix composites was successfully fabricated via the Al-KBF₄-K₂ZrF₆ system.The influence of different plastic deformation process on the microstructure and mechanical properties of the composites was studied.The main findings are as follows:?1?The average size of the in-situ ZrB₂ reinforced particles is 100 nm,mainly concentrated at the grain boundaries.?2?The effect of ZrB₂ particles on the grain size of the composites shows that the higher the content of ZrB₂ particles,the more obvious the grain refinement effect.When the mass fraction of ZrB₂ particles is 3wt.%,the average size of the matrix grains is 30?m.However,the grain refinement effect was weakened of ZrB₂/6061 aluminum matrix composites when particle mass fraction was 5wt.%.?3?The effect of ZrB₂ particles on the mechanical properties of the composites shows that due to the introduction of ZrB₂ particles,the true stress of the composites is increased by31.2%compared to that of the 6061A1 alloy,and the elongation is reduced by 14%.The Brinell hardness of the composite is 52.32 HBW,which is 31%higher than the hardness of39.8 HBW of the 6061A1 matrix.It shows that the in-situ ZrB₂/6061A1 composite material has better mechanical properties and hardness than the matrix material.?4?The results of plastic deformation on the microstructure of the composites show that after plastic deformation,the grain monography is fiber like,the width is 3⁵?m.The grain monography is bundled after extrusion,and the size is 5¹5?m.?5?The effect of plastic deformation on the mechanical properties of the composites shows that average Brinell hardness of the composite after extrusion was 58.62HBW,which was 12.04%higher than the 52.32 HBW of the as-cast composite,but the elongation decreased significantly by 24.1%.The true stress of the composite after rolling is 405 MPa,which is 63.3%higher than that of as-cast composites.The average Brinell hardness is 69.37HBW,which is 32.6%higher than that of as-cast composites,and its plasticity is reduced by49.6%.