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The improved wear and corrosion resistance of gray cast iron (GCI) with enhanced mechanical properties is a proven stepping stone towards the longevity of its versatile industrial applications. In this article, we have tailored the microstructural properties of GCI by alloying it with titanium (Ti) and tungsten (W) additives, which resulted in improved mechanical, wear, and corrosion resistance. The results also show the nucleation of the B-, D-, and E-type graphite flakes with the A-type graphite flake in the alloyed GCI microstructure. Additionally, the alloyed microstructure demonstrated that the ratio of the pearlite volume percentage to the ferrite volume percentage was improved from 67/33 to 87/13, whereas a reduction in the maximum graphite length and average grain size from 356 ± 31 µm to 297 ± 16 µm and 378 ± 18 µm to 349 ± 19 µm was detected. Consequently, it improved the mechanical properties and wear and corrosion resistance of alloyed GCI. A significant improvement in Brinell hardness, yield strength, and tensile strength of the modified microstructure from 213 ± 7 BHN to 272 ± 8 BHN, 260 ± 3 MPa to 310 ± 2 MPa, and 346 ± 12 MPa to 375 ± 7 MPa was achieved, respectively. The substantial reduction in the wear rate of alloyed GCI from 8.49 × 10−3 mm3/N.m to 1.59 × 10−3 mm3/N.m resulted in the upgradation of the surface roughness quality from 297.625 nm to 192.553 nm. Due to the increase in the corrosion potential from −0.5832 V to −0.4813 V, the impedance of the alloyed GCI was increased from 1545 Ohm·cm2 to 2290 Ohm·cm2. On the basis of the achieved experimental results, it is suggested that the reliability of alloyed GCI based on experimentally validated microstructural compositions can be ensured during the operation of plants and components in a severe wear and corrosive environment. It can be predicted that the proposed alloyed GCI components are capable of preventing the premature failure of high-tech components susceptible to a wear and corrosion environment. [ABSTRACT FROM AUTHOR]

Aluminum oxide nanopowder has been fabricated and characterized successfully to improve the properties of friction stir welded aluminum/titanium joints, which pose a great challenge due to the great difference in mechanical properties. Intermetallic compounds (IMCs) of large sizes formed at the welding interface are a significant problem that deteriorates joint strength due to the uncontrollable thermal effect generated in the joint. Therefore, friction stir processing was integrated with friction stir welding, in which a dissimilar lap joint of AA6061-T6 and Ti6Al4V was reinforced with γ-Al 2 O 3 nanoparticles of about 8 nm in diameter. First, several attempts were conducted to determine the most effective parameters in the welding process of the aluminum/titanium reinforced joint and then the effects of γ-Al 2 O 3 nanopowder on microstructure, mechanical properties, and weldability were analyzed and compared to a welded joint without reinforcing powder. Sound joints have been successfully produced using welding speed of 25 mm/min, and tool rotational speed of 600 rpm. Lap shear fracture load and displacement of the Al/Ti joint increased from 3.5 KN and 1.25 mm to 3.7 KN and 2.45 mm, respectively, while the hardness of the reinforced joint increased from 384 HV to 391 HV at the Al/Ti weld interface with a remarkable improvement at the Al and Ti sides. • Al/Ti FSWed joint was reinforced with aluminum oxide nanoparticles (γ-Al 2 O 3 NPs). • The effect of γ-Al 2 O 3 NPs on microstructure, mechanical properties, and strengthening of the joints was discussed. • γ-Al 2 O 3 NPs refine the grains at Al/Ti interface and reduce the thickness of Al/Ti intermetallic compounds. • γ-Al 2 O 3 NPs improve the tensile strenght, ductility, and hardness of the Al/Ti joint. [ABSTRACT FROM AUTHOR]

To accelerate the large-scale cellular automaton (CA) simulation for grain growth, a parallel CA model for grain growth was developed. The model was implemented based on the compute unified device architecture (CUDA) parallel computing platform. The model was verified by the grain growth of a single crystal and the columnar-to-equiaxed transition (CET) of an Al-7wt% Si specimen of uniform undercooling with a constant cooling rate. The grid independence of the model was verified. The grain growth of a plate-like casting of nickel-based superalloy during directional solidification process was simulated and the obtained results of grain density at each section with different heights were compared with the experimental data. The CET transition of directional solidified Al-7wt% Si cylindrical ingot was simulated. The grain texture and cooling curves were in good agreement with experimental results from the literature. Finally, high parallel performance of the CA model was obtained and evaluated. [ABSTRACT FROM AUTHOR]