Role of Surface Preparation in Corrosion Resistance due to Silane Coatings on a Magnesium Alloy

Coating of an organo-silane (Bis-1,2-(TriethoxySilyl)Ethane (BTSE)) has been observed to improve the corrosion resistance of magnesium alloy AZ91D. Three different types of surface preparations have been employed before condensing the silane coating on to the substrate. Corrosion resistance was investigated using electrochemical impedance spectroscopy (EIS). A specific alkali treatment of the substrate prior to the coating has been found to improve the corrosion resistance of the coated alloy, which has been attributed to the ability of the treatment in facilitating the condensation of a relatively compact siloxane film.

EFFECT OF CNT/TIB2 PARTICLE ON MECHANICAL, METALLURGICAL BEHAVIOUR OF MAGNESIUM (AZ91D) COMPOSITES

Carbon Nano tubes (CNT) and Titanium di Boride particles (TiB2) with different weight percentages reinforced composite magnesium alloy (AZ91D) were fabricated and the impact of changes in the mechanical and metallurgical properties of composites was assessed. Different weight percentage strengths of CNT (1.5 percent) and TiB2 particles (5 %, 10%, 15 %) were applied to AZ91D grade magnesium alloy for various stir casting system process parameters in this study. For reinforcement-matrix interfacial reactions, SiC and Al2O3 were also added. The composites with 10% TiB2 and (1.5 % CNT+1 % SiC+1% Al2O3) reinforcement show high hardness, whereas other reinforcements show increased elongation. The presence of elements revealed by energy dispersive X-ray spectroscopy also characterizes the composites using optical and scanning electron microscopy.

Effect of Plunger Speed and Solid Fraction on Automotive Component by Thixoforming Simulation

Thixoforming is a promising metal forming process to produce near net-shape components with high casting quality. Thixoforming of metallic alloy utilizes the thixotropic behaviour of the material with near globular or globular microstructure in the semi-solid condition. The solid content is between 50% to 70% before forming. In this paper, the effect of plunger speed and a solid fraction on an alternator housing was investigated by advance casting simulation software. The 3D CAD model of the alternator housing was created using SolidWorks software and AnyCasting software is utilized for the simulation of the thixoforming parameter and magnesium alloy (AZ91D) is the material used. The simulation had been done by varying the plunger speed, temperature (solid fraction) of the material, and both Power Law and Bingham Viscosity model are used in the simulation to identify the defect prediction at the end. The simulation result shows that laminar filling in semi-solid slurry able to achieved by controlling the plunger speed and temperature. Slower speed and lower melt temperatures are preferable in thixoforming. Therefore, a solid fraction of the material, plunger speed, and solidification rate do influence the filling behaviour of the casting of semi-solid metal.