Mechanical and Corrosion Behavior of Friction Stir Welded AA 6063 Alloy

Friction stir welding (FSW) is considered to be the most significant development in solid state metal joining processes. This joining technique is energy efficient, environmentally friendly, and versatile. In particular, it can be used to join high-strength aerospace aluminum alloys and other metallic alloys that are hard to weld by conventional fusion welding. The project aims to join Aluminum 6063 alloy plates by FSW and emphasize the (1) mechanisms responsible for the formation of welds without any defects, microstructural refinement, and (2) effects of FSW parameters on resultant microstructure, mechanical, and corrosion properties.

Effect of Heat Treatment on the Mechanical and Corrosion Properties of Mg–Zn–Ga Biodegradable Mg Alloys

Mg alloys have mechanical properties similar to those of human bones, and have been studied extensively because of their potential use in biodegradable medical implants. In this study, the influence of different heat treatment regimens on the microstructure and mechanical and corrosion properties of biodegradable Mg–Zn–Ga alloys was investigated, because Ga is effective in the treatment of disorders associated with accelerated bone loss. Solid–solution heat treatment (SSHT) enhanced the mechanical properties of these alloys, and a low corrosion rate in Hanks’ solution was achieved because of the decrease in the cathodic-phase content after SSHT. Thus, the Mg–4 wt.% Zn–4 wt.% Ga–0.5 wt.% Y alloy after 18 h of SSHT at 350 °C (ultimate tensile strength: 207 MPa; yield strength: 97 MPa; elongation at fracture: 7.5%; corrosion rate: 0.27 mm/year) was recommended for low-loaded orthopedic implants.

The effect of eggshell as a reinforcement on the mechanical and Corrosion properties of Mg-Zn-Mn matrix composite

Magnesium is a promising lightweight metal required in many industries such as automobile, aerospace, electronics, etc. It is also a biodegradable material, which eliminates the secondary removal procedure of the implant. Furthermore, its mechanical properties are similar to the mechanical properties of human bone. In this research, eggshells were used as an environmentally friendly composite reinforcement material in the Mg-2.5Zn-1Mn matrix. Composites were prepared using the powder metallurgy route. The effect of eggshells on the morphology, mechanical, and corrosion behaviour of Mg-2.5Zn-1Mn alloy was investigated. The results revealed an enhancement in grain refining ability and mechanical properties of Mg-2.5Zn-1Mn with eggshell additives. The corrosion behaviour improved at a higher percentage of eggshells (10%).

Causes of Structural Heterogeneity in High-Strength OCTG Tubes and Minimizing Their Impact on Sulfide Stress Corrosion Cracking Resistance

High-strength oil country tubular goods (OCTG) like C110, according to standard API 5CT (yield strength at least 758 MPa), are subject to requirements in terms of mechanical and corrosion properties. In this work, we studied the microstructure of seamless casing tubes made of class C110 high-strength steel with a 194.5 mm diameter and 19.7 mm wall thickness, and its influence on sulfide stress corrosion cracking (SSC). Casing tubes were obtained from continuous billets by screw piercing with preliminary quenching and tempering. It was shown that cracking during the tests always begins from the inner surface of the tube. Rough segregation bands were found on the inner tube surface, which occupies about a third of the thickness of the wall. To increase the resistance of 0.3C-Cr-Mn-Mo + 0.15(V + Nb + Ti) steel to SSC, primary recommendations for adjusting the chemical composition, production technology and heat treatment were developed.