Laser Ablation Study of Cutting Ceramics with Consideration of the Beam Inclination Angle.

Silicon alumina nitride (SiAlON) and alumina toughened zirconia (ATZ) ceramics are applied for ceramic cutting tools to machine, e.g., cast iron, nickel base alloys and other difficult-to-machine materials.

Digitisation of metal AM for part microstructure and property control.

Metal additive manufacturing, which uses a layer-by-layer approach to fabricate parts, has many potential advantages over conventional techniques, including the ability to produced complex geometries, fast new design part production, personalised production, have lower cost and produce less material waste. While these advantages make AM an attractive option for industry, determining process parameters which result in specific properties, such as the level of porosity and tensile strength, can be a long and costly endeavour. In this review, the state-of-the-art in the control of part properties in AM is examined, including the effect of microstructure on part properties.

Microstructures and Mechanical Properties of Hybrid, Additively Manufactured TiAlV after Thermomechanical Processing.

In the present study, we propose a hybrid manufacturing route to produce high-quality TiAlV parts, combining additive powder laser directed energy deposition (L-DED) for manufacturing of preforms, with subsequent hot forging as a thermomechanical processing (TMP) step. After L-DED, the material was hot formed at two different temperatures (930 °C and 1070 °C) and subsequently heat-treated for stress relief annealing. Tensile tests were performed on small sub-samples, taking into account different sample orientations with respect to the L-DED build direction and resulting in very good tensile strengths and ductility properties, similar or superior to the forged material.

Integrated Forming and Surface Engineering of Disc Springs by Inducing Residual Stresses by Incremental Sheet Forming.

Disc springs are conical annular discs, which are characterized by a high spring force with a small spring travel and good space utilization. In operation, they must meet high demands on the stability of the spring characteristic and the fatigue strength. Under loading, tensile stresses occur which limit the possible applications of disc springs.

Comparison of Microstructure and Mechanical Properties of Scalmalloy Produced by Selective Laser Melting and Laser Metal Deposition.

The second-generation aluminum-magnesium-scandium (Al-Mg-Sc) alloy, which is often referred to as Scalmalloy, has been developed as a high-strength aluminum alloy for selective laser melting (SLM). The high-cooling rates of melt pools during SLM establishes the thermodynamic conditions for a fine-grained crack-free aluminum structure saturated with fine precipitates of the ceramic phase Al₃-Sc. The precipitation allows tensile and fatigue strength of Scalmalloy to exceed those of AlSi10Mg by ~70%.

Development of a Model for Dynamic Recrystallization Consistent with the Second Derivative Criterion.

Dynamic recrystallization (DRX) processes are widely used in industrial hot working operations, not only to keep the forming forces low but also to control the microstructure and final properties of the workpiece. According to the second derivative criterion (SDC) by Poliak and Jonas, the onset of DRX can be detected from an inflection point in the strain-hardening rate as a function of flow stress. Various models are available that can predict the evolution of flow stress from incipient plastic flow up to steady-state deformation in the presence of DRX.