Synthesis and mechanical behavior of nanostructured Al 5083/n-TiB₂ metal matrix composites

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• 作者：Meijuan Li^a ; ^b ; Kaka Ma^b ; ^c ; Lin Jiang^b ; ^c ; Hanry Yang^b ; ^d ; Enrique J. Lavernia^b ; ^c ; Lianmeng Zhang^a ; Julie M. Schoenung^b ; ^c ; ^{julie.schoenung@uci.edu" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Nanostructure ; Al metal matrix composite ; Spark plasma sintering ; Mechanical properties
• 刊名：Materials Science & Engineering A
• 出版年：2016
• 出版时间：22 February 2016
• 年：2016
• 卷：656
• 期：Complete
• 页码：241-248
• 全文大小：2729 K

文摘

Nanostructured Al 5083-based composites with nano-TiB₂ reinforcement particles were fabricated via cryomilling and spark plasma sintering (SPS). TEM observation revealed that the Al matrix consists of equiaxed nano-grains (average size, ∼74 nm), and the reinforcement, TiB₂ nanoparticles (n-TiB₂), was distributed discretely and homogeneously in the Al matrix. The interface between the Al-matrix and n-TiB₂ appears to be free of defects, and no obvious discontinuities were observed. The composite exhibits a compressive strength of 817 MPa with 6.0% strain-to-failure. The strength is 20% higher than that of an equivalent SPS consolidated Al 5083 without reinforcement. Nanoindentation was used in our study to provide fundamental insight into the local microscopic mechanical properties. The strengthening mechanisms of the composites are analyzed taking into account the grain boundaries, the Orowan strengthening from the n-TiB₂ particles and dispersoids such as Al₂O₃, AlN and Al₆Mn, as well as geometrically necessary dislocations induced in the matrix by the nano-TiB₂ particles.