Preparation and investigation of Al–4 wt % B4C nanocomposite powders using mechanical milling

Abstract

Boron carbide nanoparticles were produced using commercially available boron carbide powder (0•8 μm). Mechanical milling was used to synthesize Al nanostructured powder in a planetary ball-mill under argon atmosphere up to 20 h. The same process was applied for Al-4 wt % B 4 C nanocomposite powders to explore the role of nanosize reinforcements on mechanical milling stages. Scanning electron microscopy (SEM) analysis as well as apparent density measurements were used to optimize the milling time needed for completion of the mechanical milling process. The results show that the addition of boron carbide particles accelerate the milling process, leading to a faster work hardening rate and fracture of aluminum matrix. FE-SEM images show that distribution of boron carbide particles in aluminum matrix reaches a full homogeneity when steady state takes place. The better distribution of reinforcement throughout the matrix would increase hardness of the powder. To study the compressibility of milled powder, modified heckel equation was used to consider the pressure effect on yield strength as well as reinforcing role of B 4 C particles. For better distribution of reinforcement throughout the matrix, r, modified heckel equation was used to consider the pressure effect on yield strength as well as reinforcing role of B 4 C particles.

Using B4C Nanoparticles to Enhance Thermal and Mechanical Response of Aluminum

“…The Al-B 4 C composites are used in bicycle frames, bullet proof vests, armor tanks, containment of nuclear waste, neutron absorbers in nuclear power plants, transportation applications, etc. owing to their high hardness, low density, and excellent thermal and chemical stability [ 9 , 10 ]. Recently, Al-B 4 C composites were prepared through different techniques: stir casting [ 11 ], squeeze casting [ 12 ], powder metallurgy method [ 13 ], spark plasma sintering [ 14 ], and microwave sintering [ 15 ].…”

Microstructure and mechanical properties of aluminium-graphene composite powders produced by mechanical milling

“…For FCC metals, it has been indicated that the intensity ratio of (111) to (200), I(111)/ I(200), can reflect the change in crystallographic orientation of particles in the ball milling process. While for BCC metals, I(110)/ I(200) is used (Razavi-Tousi and Szpunar 2015; Alizadeh et al 2011). As shown in Fig.…”

“…This process is faster for the Al-GNSs composite due to the aforementioned localised stress induced by the addition of GNSs. This could be explained by considering the anisotropy in the elastic modulus of a single aluminium crystal (Alizadeh et al 2011). To be specific, the aluminium grains/particles tend to be deformed in the soft direction (111), which is perpendicular to the collision direction of milling balls.…”

Effect of ball size on steady state of aluminum powder and efficiency of impacts during milling

“…Despite the trend of the changes in the shape and size of the particles, the A change in crystallographic orientation of particles can also be used to monitor the milling progress. It has been proved that the ratio of intensity of (111) to (100) reflections for FCC metals [8,10,35,36], and the ratio of (110) to (200) reflections for BCC metals [11] can reveal changes in orientation and morphology of particles during milling. Fig.…”

“…D. R. Amador et al ascribed the evolution of texture during ball milling of metallic powders to the presence of so called "soft" directions [11]. They explained the preferred orientation based on the difference in elastic modules of different directions of crystalline materials, the idea that was later echoed in other works [10,36]. The authors of the present work found this explanation unconvincing because plastic deformation of metals is based on the movement of dislocations rather than the effect of elastic modules.…”