In-Depth Comparison of an Industrially Extruded Powder and Ingot Al Alloys

An industrial press was used to consolidate compacted aluminum powder with a nominal diameter in the range of 1 µm. Direct and indirect hot-extrusion processes were used, and suitable process parameters were determined from heating conditions, ram speeds and billet temperatures. For comparison, a direct-extrusion press for hot extrusion of a conventional aluminum alloy AA 1050 was used. The extruded Al powder showed better mechanical properties and showed a thermal stability of the mechanical properties after annealing treatments. To increase the theoretical density of the directly extruded Al powder, single-hit hot-compression tests were carried out. Activation energies for hot forming were calculated from hot-compression tests carried out in the temperature range 300–580 °C, at different strain rates. Processing maps were used to demonstrate safe hot-working conditions, to obtain an optimal microstructure after hot forming of extruded Al powder.

Structural Simulation and Optimization of Diesel Engine Piston Material using ANSYS

During the combustion of fuel in diesel engine, high temperature and pressure will be created as engine runs at high speed and loads. This results in development of high thermal and structural stresses in the piston and if these stresses exceed the design value, failure of piston may take place. To avoid these failures, intensity of stresses should be avoided. In this work an attempt is made to reduce the intensity of stresses by replacing conventional aluminum alloy material of piston with aluminum silicon carbide composite by commercial analysis software package ANSYS

A Review on Development and Properties of GLARE, an Advanced Aircraft Material

The history of GLARE laminate was introduced. Through comparison with conventional aluminum alloy sheets, the excellent performance of GLARE as a new generation aeronautic material is discussed. The properties and application of GLARE in large civil aircraft indicates that new composite materials such as GLARE will replace bulk aluminum alloy in future aircraft structure. With the continuous development of material technologies, a trend of developing high strength and low cost composite materials will lead aviation industry to a new stage.

Alloy Design for Enhancing the Fracture Resistance of Heat Treated High Pressure Die-Castings

Recently, heat treatment technologies have been developed by the CSIRO Light Metals Flagship in Australia that allow the 0.2% proof stress of conventional aluminum alloy high pressure diecastings (HPDC’s) to be more than doubled without encountering problems with blistering or dimensional instability [1,2]. A range of other properties may also be improved such as fatigue resistance, thermal conductivity and fracture resistance. However, the current commercial HPDC Al-Si-Cu alloys have not been developed to exploit heat treatment or to optimize these specific mechanical properties, and one potential limitation of heat treating HPDC’s is that fracture resistance may be reduced as strength is increased. The current paper presents the outcomes of a program aimed at developing highly castable, secondary Al-Si-Cu HPDC alloys which display significantly enhanced ductility and fracture resistance in both the as-cast and heat treated conditions. Kahn-type tear tests were conducted to compare the fracture resistance of the conventional A380 alloy with a selection of the newly developed compositions. A comparison has also been made with the current permanent mold cast aluminium alloys and it is shown that the new HPDC compositions typically display higher levels of both tensile properties and fracture resistance.

An Elasto-Plastic Reformulation of the Theory of Critical Distances to Estimate Lifetime of Notched Components Failing in the Low/Medium-Cycle Fatigue Regime

This paper is concerned with a novel elasto-plastic reformulation of the Theory of Critical Distances (TCD) specifically devised to estimate lifetime of notched metallic materials (ferrous and nonferrous) failing in the low/medium-cycle fatigue regime. We used the classic Manson–Coffin and Smith–Topper–Watson approaches, but applied in conjunction with the TCD. We assumed that the material’s critical distance is a constant whose value does not depend on either the sharpness of the notch or on the number of cycles to failure. The accuracy and reliability of the proposed approach was checked by using a number of experimental results generated by testing cylindrical specimens made of En3B, which is a commercial low-carbon steel, and Al6082, which is a conventional aluminum alloy, containing different geometrical features and tested at applied load ratios of R=−1 and R=0. The resulting predictions of fatigue life were highly accurate, giving estimates falling within an error factor (in lifetime) of about 2. This result is undoubtedly encouraging, especially in light of the fact that the pieces of experimental information needed to calibrate our method can easily be generated by using standard testing equipment, and the necessary stress/strain fields acting on the fatigue process zone can be determined by directly postprocessing elasto-plastic finite element results.