The use of aluminum alloys for lightweighting in the automotive industry is becoming widespread. In this study, Johnson–Cook plasticity and damage model parameters were determined to predict the plasticity and damage behavior of 6181A-T4 sheet material using finite element analysis software. Uniaxial tensile tests were performed at four different deformation rates (0.0083–0.333 s⁻¹) using tensile test specimens with four different triaxiality values (0.33, 0.36, 0.45, and 0.74). For a 3 mm thick 6181A-T4 aluminum alloy sheet, Johnson–Cook plasticity parameters were determined by the curve fitting method, and damage parameters were optimized using LS-OPT 7.0 software. Finite element analyses using Johnson–Cook plasticity and damage model parameters were compared with the experimental results, and it was observed that the finite element analyses produced very successful predictions. With the increase in strain rate, the yield strength increased, while the tensile strength showed limited change; uniform elongation, coefficient of hardening, and toughness showed a decreasing trend, and the fracture mode showed a transition from ductile to more brittle behavior. The coefficient of determination (R²) values between the Johnson–Cook model and the experimental data ranged from 0.8601 to 0.9837 depending on the strain-rate value.

The influences of the strain rate on the tensile properties and fracture behaviour of DP600 and DP780 advanced high-strength sheet steels have been studied. The variation of their mechanical properties depending on the strain rate have been researched by applying uniaxial tensile tests at three different strain rates (0.001, 0.01, 0.06 s⁻¹). The influences of strain rate on fracture behaviour have been investigated by displaying the fracture surfaces of the material. Strain rate increase has been determined to increase the yield strength, tensile strength, total elongation and hardening rate. The strain hardening coefficient has been found not to be significantly affected by the strain rate. It has been determined that, the fracture has occurred faster during necking while load-carrying capacity has increased with strain rate increase.

The effect of temperature has been investigated on the mechanical properties and fracture behaviour of DP1000 advanced high-strength steel. The variation of the mechanical properties depending on temperature has been determined by performing uniaxial tensile tests at the temperatures of 25, 100, 200, 300°C at the rolling directions of 0° (rolling), 45° (diagonal), and 90° (transverse) at the strain rate of 0.0083 s⁻¹. The yield strength and tensile strength have showed a slight decrease tendency between 25 and 200°C, but the highest value has been reached by showing an increase at 300°C temperature. The amount of elongation has not been affected significantly with the increase of the temperature. While hardening coefficient has increased due to the rising temperature, no effect has been observed on strength coefficient between 25 and 100°C, but an increase has occurred at higher temperature values.

In this study, powder metallurgical steel samples containing 1.5% C by weight were produced by sintering in a vacuum atmosphere at 1200°C. The impact test and dry sliding wear test specimens were prepared in accordance with ISO 5754 and ASTM G-99 standards, respectively. The wear and impact toughness properties of spherical cementite in the bainitic matrix (SCBM) microstructured specimens produced with different heat treatment routes were compared with pearlite plus primary cementite, fully tempered martensitic, fully bainitic and spherical cementite microstructured specimens in ferritic matrix (SCFM). Microstructural characterisations of all specimens were performed by SEM, EBSD and XRD analyses methods. Compared to fully tempered martensitic and fully bainitic microstructured specimens with similar hardness, both the dry sliding wear and the impact toughness properties of the specimens having SCBM microstructures were improved with the increased austempering time after spheroidisation treatment.

In this study, pure aluminum powders were turned into bulk material using equal channel angular densification (ECAD)/equal channel angular pressing (ECAP) and further deformed up to 16 passes at 100 °C. For comparison, pure aluminum powders were also compacted in a mold without ECAD/ECAP process at the same temperature. The microstructures were characterized using TEM for grain size and shape measurements. In general, the grains were finer in the specimens processed by ECAD/ECAP than in the compacted specimen without ECAD/ECAP process. The high density which is very close to the full density of pure aluminum (2.7 g × cm^-3) was reached at the second pass of ECAD/ECAP. By the application of ECAD/ECAP process, severe plastic deformation enabled particles to be compacted into fully dense materials at much lower temperatures and shorter times, compared to the conventional sintering process. The ECAD/ECAP process was shown to provide an effective method for producing nano-sized grain and nearly full densification in aluminum powder.