TiN-Al Composite Coatings on A356 Alloy by Mechanical Alloying

Abstract

The TiN-Al composite coatings on A356 alloy were successfully synthesized by mechanical alloying (MA) of Al, TiN and C powders under argon atmosphere. Meanwhile, the optimal parameters for mechanical milling processing were determined by changing the material ratio (Al: TiN: C), milling time and the ball-to-powder weight ratio, which might have a significant improvement on the wear resistance of A356 alloys. The microstructures and mechanical properties of A356 alloy samples with TiN-Al composite coatings were characterized by means of X-ray diffraction (XRD), scanning electron microscope (SEM) equipped with energy dispersive X-ray spectroscopy (EDS) and Brinell hardness test. It was found that under the optimal conditions, i.e. the material ratio of (Al: TiN: C= 17.5:1.5:1), the ball-to-powder weight ratio of 14:1 and the milling duration of 12 h, the Brinell hardness of sample-6 could be remarkably increased to 143.80 HBW. With the TiN-Al coatings fabricated by MA process, the mechanical properties of aluminum alloys could be significantly improved.

Effect of Deformation Temperature on Texture Evolution of TLM Titanium Alloy

“…Meanwhile, the dynamic recrystallization process generates a number of nuclei, which originate at the old grain boundaries, with various orientations. The fast growth of some new crystal nuclei with certain preferred orientations determines the formation of dynamic recrystallization textures [26]. In the present study, as seen from the microstructure development in different deformation temperature, the microstructure are consisted of elongate and flat grains which show the DR features and DRX grains originated at the boundaries of deformation grains in case of 750°C deformation temperature, and deformation grains and DRX grains in the interior of original grains and along the original grains boundary in case of 800°C, and deformation grains and DRX grain growth in case of 850°C.…”

Mechanosynthesis of High-Nitrogen Steels Strengthened by Secondary Titanium Nitrides

“…Titanium nitrides have the highest heat of formation (HF); such HF characterizes the bonding forces of the metal with nitrogen. This makes titanium nitrides a promising hardening phase in steel composites [ 4 , 27 , 28 ].…”