Aluminium boride particles have been produced

Aluminium boride particles have been produced within Al-3wt%B alloy via melting and cooling experiments. Boride particles have dispersed in the aluminium matrix homogeneously. In general, particles have been found to have a high aspect ratio of flakes or platelets. The width of platelets was several hundred microns, while their thickness was only a few microns. The high aspect ratio flakes are attributed to be AlB2 which were formed by direct nucleation and growth process from the melt below the peritectic transition temperature due to fast cooling from 1300 oC to 700 oC. Non-flake shape particles (cubic or tetrahedral) have also been found in the microstructure. This was attributed to the nucleation of higher boride particles above the peritectic transformation temperature. Formation of non-flake boride particles is not desirable in manufacturing metal matrix composite, and therefore, their formation should be avoided by faster cooling than obtained in this work. The present work has demonstrated that a new family of in-situ metal matrix composites (MMCs) based on high aspect ratio AlB2 can be developed. Preparation of these MMCs involves the conversion of low aspect ratio AlB2 to high aspect ratio AlB2 by controlled heating and cooling processes. This conversion is associated with the Al(L) + AlB12 AlB2 peritectic transformation. Aluminium matrix composites reinforced with ceramic particles exhibit a lower wear rate than pure aluminium or aluminium alloys. However, the types of reinforcement particles do not significantly influence the wear and friction properties of the composites. On the other hand, the volume fraction of reinforcement does affect the wear rate excessively. It has been claimed that in an in-situ AlB2 reinforced Al matrix composite, at a volume fraction of 20 % reinforcement, the composite showed an 80 % increase in strength compared to 10 % reinforcement. An SEM image of deeply etched Al-% 3wt% B alloy produced by argon quenching from 1300 oC is shown in Fig.3, which presents the resulting microstructure with AlB2 flake reinforcements embedded in the aluminium matrix. The spongy view of the matrix is due to the hasty etching effect of the 10 %HCl solution used for deep etching processes. If you are looking for high quality, high purity and cost-effective Aluminum Boride, or if you require the latest price of Aluminum Boride, please feel free to email contact mis-asia.

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