Pseudo-in-situ stir casting: a new method for production of aluminum matrix composites with bimodal-sized B4C reinforcement
来源期刊：International Journal of Minerals Metallurgy and Materials2016年第8期
论文作者：Mohammad Raei Masoud Panjepour Mahmood Meratian
文章页码：981 - 990
摘 要：A new method was applied to produce an Al-0.5wt%Ti-0.3wt%Zr/5vol%B4C composite via stir casting with the aim of characterizing the microstructure of the resulting composite. For the production of the composite, large B4 C particles（larger than 75 μm） with no pre-heating were added to the stirred melt. Reflected-light microscopy, X-ray diffraction, scanning electron microscopy, field-emission scanning electron microscopy, laser particle size analysis, and image analysis using the Clemex software were performed on the cast samples for microstructural analysis and phase detection. The results revealed that as a consequence of thermal shock, B4 C particle breakage occurred in the melt. The mechanism proposed for this phenomenon is that the exerted thermal shock in combination with the low thermal shock resistance of B4 C and large size of the added B4 C particles were the three key parameters responsible for B4 C particle breakage. This breakage introduced small particles with sizes less than 10 μm and with no contamination on their surfaces into the melt. The mean particle distance measured via image analysis was approximately 60 μm. The coefficient of variation index, which was used as a measure of particle distribution homogeneity, showed some variations, indicating a relatively homogeneous distribution.
Mohammad Raei，Masoud Panjepour，Mahmood Meratian
Department of Materials Engineering, Isfahan University of Technology
摘 要：A new method was applied to produce an Al-0.5wt%Ti-0.3wt%Zr/5vol%B4C composite via stir casting with the aim of characterizing the microstructure of the resulting composite. For the production of the composite, large B4 C particles（larger than 75 μm） with no pre-heating were added to the stirred melt. Reflected-light microscopy, X-ray diffraction, scanning electron microscopy, field-emission scanning electron microscopy, laser particle size analysis, and image analysis using the Clemex software were performed on the cast samples for microstructural analysis and phase detection. The results revealed that as a consequence of thermal shock, B4 C particle breakage occurred in the melt. The mechanism proposed for this phenomenon is that the exerted thermal shock in combination with the low thermal shock resistance of B4 C and large size of the added B4 C particles were the three key parameters responsible for B4 C particle breakage. This breakage introduced small particles with sizes less than 10 μm and with no contamination on their surfaces into the melt. The mean particle distance measured via image analysis was approximately 60 μm. The coefficient of variation index, which was used as a measure of particle distribution homogeneity, showed some variations, indicating a relatively homogeneous distribution.
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