In this study, direct laser deposition (DLD) of nickel-based superalloy powders (Inconel 625) on structural steel (42CrMo4) was analysed. Cladding layers were produced by varying the main processing conditions: laser power, scanning speed, feed rate, and preheating. The processing window was established based on conditions that assured deposited layers without significant structural defects and a dilution between 15 and 30%. Scanning electron microscopy, energy dispersive spectroscopy, and electron backscatter diffraction were performed for microstructural characterisation. The Vickers hardness test was used to analyse the mechanical response of the optimised cladding layers. The results highlight the influence of preheating on the microstructure and mechanical responses, particularly in the heat-affected zone. Substrate preheating to 300 °C has a strong effect on the cladding/substrate interface region, affecting the microstructure and the hardness distribution. Preheating also reduced the formation of the deleterious Laves phase in the cladding and altered the martensite microstructure in the heat-affected zone, with a substantial decrease in hardness.

The current increase in power density, contact load, and speeds have imposed new challenges on elastohydrodynamic lubrication (EHL) contact models. To overcome possible EHL limitations under such conditions, the present work presents a unified thermal plasto-elastohydrodynamic lubrication (TPEHL) model for circular contact with real surface roughness capable to simulate the different lubrication regimes. Among the main characteristics of the proposed model, one should mention the minimal implementation changes in standard EHL models; there is no need for a preliminary assessment to verify whether thermal and plastic effects are negligible (or not) since these effects will naturally take place in the simulations, and good agreement between the predictions using the model and the experimental measurements.

Foreword The International Conference on Gears in Garching near Munich, Germany, is an established platform for researchers on and manufacturers of gears and transmission systems. At the 10th issue of the conference in September of 2023, gear experts discussed the latest developments and research results from the powertrain industry and academia. Given the increasing challenges of climate change and its impacts, acting in compliance with the UN Sustainable Development Goals is mandatory for all engineers today. Gear engineers must consider these objectives in their research and development activities and provide solutions that meet the technical requirements and contribute to achieving the UN goals. Greenhouse gas (GHG) emission is a primary driver for climate change. Reducing GHG emissions should be an urgent action for the combat against climate change. Therefore, the research on efficiency is assigned a key role. Several contributions in this report discuss the possibilities for further improvement in efficiency from different points of view, like gear design or lubrication. Other subjects of the conferences are Responsible Consumption and Production. H...