In situ development of AlB_x/AA6060 and AA5083 alloys cast composites

详细信息    查看全文

• 作者：P. Moldovan^a ; ^{cavnic2010@gmail.com" class="auth_mail" title="E-mail the corresponding author} ; D.V. Dragut^b ; ^{dragutdumitruvalentin@yahoo.com" class="auth_mail" title="E-mail the corresponding author} ; ^{dragutv@imnr.ro" class="auth_mail" title="E-mail the corresponding author} ; M. Butu^a ; ^{mihaibutu@yahoo.com" class="auth_mail" title="E-mail the corresponding author} ; L.M. Besea^a ; ^{besealiviu@yahoo.com" class="auth_mail" title="E-mail the corresponding author} ; E.A. Preda^a ; ^{andaelenapreda@yahoo.com" class="auth_mail" title="E-mail the corresponding author}
• 关键词：A. Metal-matrix composites (MMCs) ; A. Particle reinforcement ; D. Electron microscopy ; B. Microstructures ; AlB2
• 刊名：Composites Part B: Engineering
• 出版年：2016
• 出版时间：15 July 2016
• 年：2016
• 卷：97
• 期：Complete
• 页码：9-17
• 全文大小：3453 K

文摘

Al – AlB_{x (x = 2,12)}, AA6060 – AlB_{x (x = 2,12)} and AA5083 – AlB_{x (x = 2,12)} composites with 3 wt % AlB_x particles were developed by in-situ reaction of molten aluminium and alloys (AA5083 and AA6060) with inorganic salt KBF₄ at a temperature of 900 °C. The chemical reaction produces boron, which dissolves into the molten alloy and subsequently forms aluminium borides (AlB₂ and AlB₁₂). The thermodynamic properties of the reactions are calculated by HSC Chemistry 6.0 software. In the case of aluminium matrix the melt solidified in the crucible, between 980 °C and 200 °C, in order to develop the peritectic reaction AlB₁₂ + 5Al_(l) = 6AlB₂.

It was found that both in the case of aluminium and aluminium alloys the peritectic reaction occurs partially. The composites were characterised by SEM and XRD analysis. The stress-strain measurement showed 8% improvement towards the matrix alloys. The fracture features of composites were examined using SEM analysis. Ductile and brittle locally fractography is revealed. Composites exhibited a higher resistance to crack initiation than the matrix alloys. The results obtained in the experiments and analysis helps to clarify the mechanism of interaction between liquid aluminium and KBF₄ at high temperatures.