Ballistic behavior of boron carbide reinforced AA7075 aluminium alloy using friction stir processing – An experimental study and analytical approach

Abstract

High strength-to-weight ratio of non-ferrous alloys, such as aluminium, magnesium and titanium alloys, are considered to be possible replacement of widely accepted steels in transportation and automobile sectors. Among these alloys, magnesium is self explosive and titanium is costlier, and aluminium is most likely to replace steels. Application of aluminium or its alloys is also thought of as an appropriate replacement in defence field, especially to enhance the easiness in mobility of combat vehicles while maintaining the same standard as that of conventional armour grade steels. Hence most of the investigations have been confined to aluminium or its alloys as base material and open an era of developing the newer composite materials to address the major limitation, i.e. tribological properties. The surface composites can be fabricated by incorporating the ceramic carbides like silicon carbide, carbides of transition metals and oxides of aluminium using surface modification techniques, such as high energy laser melt treatment, high energy electron beam irradiation and thermal spray process which are based on fusion route. These techniques yield the fusion related problems, such as interfacial reaction, pin holes, shrinkage cavities or voids and other casting related defects, and pave the way to need of an efficient technique which must be based on solid state. Recently developed friction stir processing technique was used in the present investigation for surface modification of AA7075 aluminum alloy, which is an alternative to steels. In the present investigation, 160 mm sized boron carbide powder was procured and was reduced to 60 mm and 30 mm using high energy ball mill. Subsequently these powders were used to fabricate the surface composites using friction stir processing.Ballistic performance testing as per the military standard (JIS.0108.01) was carried out. In the present work, an analytical method of predicting the ballistic behavior of surface composites was developed. This method was based on energy balance, i.e., the initial energy of impact is same as that of energy absorbed by multi layers. An attempt also has been made to validate the analytical results with the experimental findings. Variation between the analytical and experimental results may be accounted due to the assumptions considering such as isotropic behavior of target and shearing area of contact as cylindrical instead of conical interface As the analytical model yields the ballistic performance in the closer proximity of experimentally obtained, it can be considered to be an approximation to evaluate the ballistic performance of targets.

Friction stir process: a green fabrication technique for surface composites—a review paper

“…The hybrid composites consist of more than one reinforcement particles. The Al/B 4 C/TiC hybrid composites [78] exhibited higher tensile strength as compared to TiC fabricated composite as shown in Fig. 12.…”

Microstructural, mechanical and wear characteristics of aluminum matrix composites fabricated by friction stir processing

“…When aluminum alloys are subjected to FSW/FSP, being a material with high stacking fault energy (γ SFE ≈ 160-200) [88], generally CDRX acts as main grain refining mechanism. Fine grains with more HAGBs are formed in the fabricated composites as a result of CDRX [35,43,45,51,61,89,90]. At the time of deformation of metal at elevated temperature, two opposite phenomena take place simultaneously, i.e., formation of dislocation and dynamic recovery, which determines the dislocation density in the material.…”

“…Sudhakar et al [90] prepared AA7075 matrix composite by adding different sizes of B 4 C particles and observed that penetration of projectile during ballistic impact test reduced with reduction in particle size. The hard particles acted as barrier to the projectile movement, and consequently, the projectile tip was damaged due to abrasive nature of the particles.…”

Tribological, structural and mechanical characteristics of friction stir processed aluminium-based matrix composites reinforced with stainless steel micro-particles

“…It is, therefore, certain that in the future, steel might go into extinction wherein high strength and low-density materials such as aluminium, titanium, and magnesium might replace the steel. On this awareness and since titanium is very costly and magnesium is self-explosive, therefore aluminium might be the one that will likely replace steel in some of the prominent industries where steel functions today such as transportation, aerospace, automobiles, and defense sectors (Ikumapayi et al, 2019b;Sudhakar et al, 2016). The utilization of any of these engineering materials effectively and efficiently is very paramount for the manufacturing and designing of various structures, machines as well as vehicles, etc.…”