Yunus Turen

Mechanical Properties and Corrosion Behavior of As-Cast Mg-Zn-Zr-(La) Magnesium Alloys

The effects of La content on the mechanical properties and corrosion behavior of as-cast Mg-Zn-Zr (ZK) magnesium alloys were investigated. The results showed that La addition to ZK60 alloy resulted in a considerable grain refinement and an increase in the volume fraction of second phases by formation of Mg-Zn-La ternary phase. The tensile tests were performed at both room and elevated temperatures. At room temperature, the yield and tensile strengths and elongation-to-fracture significantly increased with 0.2xa0wt.% La addition, then deteriorated slightly with increasing La additions above 0.2xa0wt.%. At 200xa0°C, the yield and tensile strengths continually improved and elongation-to-fracture decreased with increasing La content due to the presence of thermally stable Mg-Zn-La phase. Immersion and electrochemical corrosion tests revealed that the formation of Mg-Zn-La phases led to a higher amount of cathodic sites and preferential corrosion propagation, and thus a decrease in the corrosion resistance of ZK60 alloys.

An investigation on dry sliding wear behaviour of pressure infiltrated AA1050-XMg/B4C composites

Abstract In this study, the effect of Mg alloying addition (1–4 wt.%) on dry sliding wear behaviour of AA1050 matrix composites was investigated. Composites were produced by the pressure infiltration technique at 800°C and had a B4C particle volume fraction of 60%. Reinforcement particles were uniformly distributed in the aluminium matrix. Compared with the AA1050 matrix, the weight loss of the composites decreased with increasing Mg content. The wear rate of the composites increased when the applied load and sliding distance were increased. The results show that when the applied load reaches critical values (30 N), the weight loss increases significantly.

Microstructure, mechanical properties and corrosion resistance of as-cast and as-extruded Mg–4Zn–1La magnesium alloy

Microstructure, mechanical properties and corrosion resistance of as-cast and as-extruded Mg–4 wt% Zn–1 wt% La magnesium alloys were investigated. The alloys were produced by low-pressure die casting method and extruded at 350xa0°C after homogenization at 400xa0°C for 24xa0h. The results show that the as-cast alloy mainly consists of primary α-Mg matrix and Mg–Zn–La ternary second phases (also called T-Phase) along grain boundaries and isolated spherical particles inside the grains. After extrusion at 350xa0°C, the average grain size decreases by 81% due to dynamic recrystallization mechanism and T-phase particles are distributed along the extrusion direction. The elongation, yield strength and tensile strength of the as-cast Mg–4Zn–1La alloy increase by 179%, 90% and 40%, respectively, as a result of the extrusion process. The as-extruded Mg–4Zn–1La alloy shows better corrosion resistance than the as-cast alloy due to increased grain boundaries and decreased content of T-phase.

Microstructure and corrosion properties of lanthanum-added AZ31 Mg alloys

In this study, the effect of lanthanum (La) on microstructure and corrosion properties of hot-rolled AZ31 Mg alloys was investigated. Light optical microscopy, scanning electron microscopy, and X-ray diffraction were applied for microstructure analysis. Potentiodynamic corrosion and immersion tests were being tried to assess the La effect on corrosion behavior. Moreover, how the rolling parameters and surface smoothness were changed of the corrosion rate was evaluated. Corrosion performance was developed by adding La and the corrosion rate was changed with the rolling speed.

Effect of Sn Addition on Corrosion Properties of As-Cast and Hot-Rolled AZ31 Magnesium Alloys

This study investigates the effect of Ti addition (0, 0.2, 0.5, 1wt%) on corrosion resistance of as-cast and hot rolled AM60 magnesium alloy. Corrosion behaviors were investigated by immersion tests and electrochemical analysis. The results showed that Ti addition altered the microstructure of as-cast AM60 magnesium alloy by decreasing the amount of β-Mg17Al12 eutectic phase. Homogenization treatment resulted in the dissolution of the most of the β-Mg17Al12 phases. Homogenized samples exhibited the lowest corrosion rate in immersion test while the best corrosion resistance was found for hot-rolled samples in electrochemical test. In hot-rolled state, Ti addition led to a slight change in the corrosion resistance of AM60 magnesium alloy.

Microstructure and Corrosion Properties of Homogenized Mg-4Zn-1La Magnesium Alloy

In this study, microstructure and corrosion behaviour of homogenized Mg-4Zn-1La magnesium alloy was investigated. Mg-4Zn-1La alloy was produced by low-pressure die casting method. Homogenization treatments were performed at 350 °C and 400 °C for 12, 18, 24 and 48 hours, followed by rapid cooling in water at room temperature. Microstructure characterizations showed that La addition led to a formation of semi-continuous network structure and islands of second phases which identified as T-phase (Mg7Zn3RE). A significant amount of second phase dissolution and an increase in a-Mg grain size with increasing both homogenization time and temperature was observed. Homogenization treatment led to an improvement in corrosion resistance of Mg-4Zn-1La alloy. Homogenization at 400 °C resulted in better corrosion resistance than homogenization at 350 °C for all homogenization duration.

Microstructure and Corrosion Properties of Homogenized AZ31 and AZ31+1%La Magnesium Alloys

Energy efficiency and decreasing emission of greenhouse gasses emerge that the importance of Mg alloys. Mg alloys can begin to supersede the steel and aluminum for structural applications, thanks to the developing of mechanical properties or corrosion resistance of Mg alloys. Rare earth metals such as Gd, Ce, Y and Nd have been utilized at AZ31 Mg alloys for this purpose in recent years. In this study, the effects of La addition and homogenization heat treatment on microstructure, hardness properties and corrosion resistance of AZ31 and modified AZ31 Mg alloys produced by low pressure die casting method were investigated.

Effect of Magnesium Additions on Composites with Al and Al – 12% Si Matrices Strengthened with B4C and Prepared by Infiltration Under Pressure

Metallographic and x-ray phase analyses are used for metal-matrix composites Al – B4C and (Al – 12% Si) – B4C with a volume fraction of 60% boron carbide prepared by infiltrating a pressed workpiece with metal under pressure. It is shown that with introduction of 1 to 4% Mg into a metal matrix composite porosity is reduced from 7 to 1%.