B4C-Al Composites Fabricated by the Powder Metallurgy Process

Abstract

Featured Application: Neutron absorber materials are used in spent-fuel storage racks, storage, and transportation casks to control the reactivity of spent nuclear fuel, allowing the storage and shipment of spent fuel at maximum packing density. Due to the large thermal neutron absorption cross-section of the nuclide B-10 and the excellent mechanical performance of aluminum, B 4 C-Al composites have the potential to serve as the neutron absorber as well as the structural function in fuel racks. This work provides an efficient method to fabricate the homogeneously mixed B 4 C-Al composites with superior yield and tensile strength.Abstract: Due to the large thermal neutron absorption cross section of 10 B, B 4 C-Al composites have been used as neutron absorbing materials in nuclear industries, which can offer not only good neutron shielding performance but also excellent mechanical properties. The distribution of B 4 C particles affects the mechanical performance and efficiency of the thermal neutron absorption of the composite materials. In this study, 15 wt % B 4 C-Al and 20 wt % B 4 C-Al composites were prepared using a powder metallurgy process, i.e., ball milling followed by pressing, sintering, hot-extrusion, and hot-rolling. The yield and tensile strengths of the composites were markedly increased with an increase in the milling energy and the percentages of B 4 C particles. Microstructure analysis and neutron radiography revealed that the high-energy ball milling induced the homogeneous distribution of B 4 C particles in the Al matrix and good bonding between the Al matrix and the B 4 C particles. The load transfer ability and mechanical properties of the composites were consequently improved. The results showed the high-energy ball milling process is an appropriate fabrication procedure to prevent the agglomeration of the reinforcement particles even if the matrix to reinforcement particle size ratio was nearly 10.

The effect of B4C reinforcements on the microstructure, mechanical properties, and wear behavior of AA7075 alloy matrix produced by squeeze casting

“…Zhang et al 18 observed that the yield and tensile strength of their 15% and 20% B 4 C reinforced aluminum MMCs increased significantly with increasing B 4 C particle ratio. Poovazhagan et al 19 found that SiC and B 4 C nanoparticle reinforcement significantly reduced the ductility and impact strength of the AA6061 matrix, while remarkably increasing the hardness and tensile strength.…”

Microstructure and Mechanical Properties of Low-Cost SiC-Reinforced Aluminum and Al4Cu Matrix Composites Produced by Sintering in Vacuum

“…Powder metallurgy is also a very efficient method applied in the recycling of metals and alloys [6]. It should also be noted that the process utilizes temperatures below the melting point of the treated material [7]. Therefore, in the process of fabricating Al/SiC composites using the powder metallurgy method, due to the low sintering temperature, the interfacial reactions between Al and SiC that cause the formation of the brittle Al 4 C 3 phase, which can degrade mechanical properties, are limited [8].…”

Nanoparticles reinforced Al-matrix composites fabricated by combination of pre-distribution and deformation: A review

“…However, in SSM, the fabrication process is not promising for applications because of its limitations in the complexity and size of the samples and high costs. For recent decades, powder metallurgy (PM) which belongs to the method (i) has been extensively used for contributing to the distribution of nanoparticles, the PM process shows no typical segregation phenomena compared with other processes, but it shows potential advantages [28][29][30]: (a) Avoiding the harmful reactions between the matrix and the nanoparticles. (b) Enabling to produce AMCs with a high-volume fraction of nanoparticles.…”