Papers by Keyword: Castability

Abstract: Iron is the main component of the earth's core, the most abundant element on the earth (about 35%), and it is relatively high in the sun and other stars. Also, it is a common and cheap metal in the manufacturing industry. Recently, with the rapid development of electric vehicles, more and more automotive companies are willing to develop new lightweight material for electric motors used in electrical vehicles. The iron–containing aluminum alloys can be considered as a good candidate, due to its great strength and electricity performance. This review describes various properties of aluminum-iron alloys including mechanical properties and electrical conductivities, as well their relation to the Fe contents. Also, metallurgical aspects of aluminum-iron alloys, including phase diagrams, equilibrium and non-equilibriun solidification, microstructure development, and castability. The further research and development work are outlined in terms of developing aluminum-iron alloys for some potential and value-added automotive applications.

Abstract: Commonly used Grade 20GL cast steel has unstable impact strength values determined on V-notched samples at –60 °C and so cannot provide reliability of cast parts at negative temperatures.

Abstract: Ni-Cr alloys are popular for dental prostheses for the reason of economy and few better characteristics in comparison to expensive gold based alloys. However, Ni-Cr alloy developed locally has higher melting point around 1400°C as compared to that of proprietary alloys. The Ni-Cr alloys contain major alloying elements in following range: 50-80 % Ni, 10-30 % Cr, 3-10 % Mo. Minor addition is made to have requisite properties suitable for dental prostheses. In this work investigation was carried out to find out optimum chemistry to have melting point of the alloy in the range of 1100-1200°C without compromising the requisite mechanical properties. Developed alloy was characterized using Scanning Electron Microscope, Inductive Coupled Spark Plasma, Hardness Tester and Differential Scanning Calorimetry. Results were analyzed and acceptable samples tested at dental labs for trial use and suitability for dental prostheses.

Abstract: Research into magnesium die-cast alloys from the Mg-Al-(Zn), Mg-Zn-(Al), Mg-rare earth (RE) and Mg-Al-RE systems is discussed. Particular attention is paid to factors influencing mechanical properties and castability. The nature and level of alloy addition is in all cases an important determinant of castability (cracking and fluidity) and mechanical properties (strength, ductility and creep resistance). The interplay of these factors shows considerable variation between different alloy systems.

Abstract: Majority structural elements from magnesium alloys are produced by means of casting. The big and complicated elements are mainly sand cast. The aim of the research was to investigate the influence of wall thickness on the castability and microstructure of modern magnesium alloy with RE and Ag additions – QE22. Eight 145x98mm plates have been cast for the research. Their designed thickness was equal: 0.5mm, 1mm, 1.5mm, 2mm, 3mm, 4mm, 5mm as well as 6mm. The parameters of microstructure constituents in each cast has been estimated quantitatively. The critical wall thickness, at which liquid alloy fill the mould cavity completely, is equal 4mm. With decreasing wall thickness, percentage of filled cavity is decreasing linearly. Mean area of grain flat section increased 7 times in the thickest plate (from 501μm² to 3773μm²). The volume fraction of eutectics as well as alloy hardness decreased in the thickest plate.

Abstract: Solidification behaviors of IC10 alloy with different titanium content were investigated by isothermal solidification method. Volume percentage of liquid and precipitation temperature of primary MC type carbide, eutectic and secondary γ′ phase were investigated. The results showed that with the increase of Ti content in the alloy, the liquidus, solidus and MC carbide formation temperatures decreased, on the contrary, the formation of γ+γ′ eutectic and secondary γ′ increased. For the IC10 alloy with 1.5% titanium content, it is earlier for the interdendritic pools to be divided into the parts. At this condition, melted portion of the alloy resided during isothermal process. As a result, the castability of the IC10 with 1.5% titanium is thus the lowest.

Abstract: To develop an aluminium alloy which may combine high thermal conductivity and good castability and anodizability, Al-(0.5~1.5)Mg-1Fe-0.5Si and Al-(1.0~1.5)Si-1Fe-1Zn alloys were assessed as potential candidates. The alloys exhibited 170~190% thermal conductivity, 60~85% fluidity, and equal or higher ultimate tensile strength compared to those of ADC12 alloy.

Abstract: Magnesium alloys are widely used in aerospace and automotive industry due to their low density, good mechanical properties and good castability. The paper presents results of the castability tests and microstructural investigations on two unmodified magnesium casting alloys, Elektron 21 and QE22. Spirals for the castability test were poured from three temperatures: 755°C, 800°C and 835°C. Volume fraction of eutectic regions and grain size in both alloys were quantitatively evaluated. Castability increased with increasing pouring temperature. Quantity of eutectics and grain size did not show straight correlation with pouring temperature.

Abstract: Magnesium alloys are widely used in automotive and aerospace industries due to their great connection of low density and good mechanical properties. They are also characterized by good castability and weldability. Their weak high temperature properties and corrosion resistance, led to development of magnesium alloys containing rare earth elements. Casting is the most popular way of manufacturing magnesium elements. However, there is a lack of investigations concerning impact of different factors on fluidity of these alloys. This paper presents results of investigations on influence of pouring temperature on castability and microstructure of QE22 and RZ5 magnesium alloys. In case of QE22 alloy, the filling length of the liquid alloy increased with the increasing pouring temperature. In RZ5 no such dependence was noted. This is probably caused by oxide films in the structure of material. Grain refinement and eutectics volume fraction also didn’t present correlation with pouring temperature.

Abstract: This Research Focused on Studying the Effect of Silicon on the Hot Tearing Susceptibility of Permanent Mould Cast AZ91E Magnesium Alloy. Varying Amounts of Silicon (0.5, 1.0 and 1.5 Wt.%) Were Added to AZ91E in the Form of an Al-53 Wt.% Si Master Alloy. the Microstructure, Grain Size and Solidification Behavior of each Alloy Were Characterized and Related to their Tensile Properties and Hot Tearing Susceptibility. the Results Showed that the Tensile Strength and the Elongation of AZ91 Alloy Decreased with the Addition of Silicon at Room Temperature, due to the Formation of Chinese Script Mg2si Particles. however, Silicon Significantly Reduced the Hot Tearing Susceptibility of AZ91E. this Was Attributed to the Reduction of the Grain Size and the Decreased Freezing Range of AZ91E, which Contributed to Improve the Interdendritic Feeding during the Last Stage of Solidification.