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In this study, pack boriding is done on AISI 4340 steel in steel containers for 3 hours at 950°C. Boriding results in the formation of FeB or Fe2B columnar microstructure at the case. Such microstructure brings about a high brittleness of the boride layer. Induction surface modification is done on Borided samples to bring down the surface hardness. We put an effort to enhance the toughness of boride layer using 30 kW power high frequency induction heat source. The toughness of borided, borided and induction surface modified specimens are evaluated by shear punch test. Cylindrical punch of 4 mm diameter is used in this test. The toughness is calculated from the load-displacement curve. Induction modified specimens exhibit 38% improvement in toughness as compared with borided specimens. This improvement in toughness may be due to blunting of acicular boride structure in to a globular structure at the interface, smooth hardness gradient and formation of single phase Fe2B microstructure as a result of induction surface modification.

The aim of this study is to synthesize a new metallic aluminum and vanadium-free titanium alloy biomaterial for better osseointegration and implantation in the physiological system. The in vitro and in vivo methods were used to examine their biological compatibility, evaluated quantitatively and qualitatively. Results of Ga-Si-Ti alloy showed a higher ultimate tensile strength, yield strength and a higher percentage of elongation and more or less equal to Young\'s modulus when compared with the Ti and Ti-Ga alloy. In vivo study, a PA view of whole-body radiography all groups exhibited a substantial difference in the linear bone density of newly formed bone. Ga-Si-Ti group showed the highest bone mineral density than Ti and Ti-Ga group in the micro CT ex vivo study. The study exhibited a significant difference between the groups and the proportion of cortical bone volume to trabecular bone volume BV/TV in percentage. This is related to the anti-resorptive action of gallium and osteoblastic property of silicon, in addition to the benefits of commercial pure-Ti alloy.

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