Overmoulding of thermoplastic composites combines the steps of thermoforming and injection moulding in an integrated manufacturing process. The combination of continuous fibre-reinforced thermoplastics with overmoulded polymer enables the manufacturing of highly functionally integrated structures with excellent mechanical properties. When performed as a one-shot process, an economically efficient manufacturing of geometrical complex lightweight parts within short cycle times is possible. However, a major challenge in the part and process design of overmoulded thermoplastic composites (OTC) is the assurance of sufficient bond strength between the composite and the overmoulded polymers. Within the framework of a simulation-based approach, this study aims to develop a methodology for predicting the bond strength in OTC using simulation data and a numerical model formulation of the bonding mechanisms. Therefore, a modelling approach for the determination of the bond strength depending on different process parameters is presented. In order to validate the bond strength model, specimens are manufactured with different process settings and mechanical tests are carried out. Overall, the results of the numerical computation are in good agreement with the experimentally determined bond strength. The proposed modelling approach enables the prediction of the local bond strength in OTC, considering the interface conditions and the processing history.

As a result of global economic and environmental change, the demand for innovative, environmentally-friendly technologies is increasing. Employing solid lubricants in rolling contacts can reduce the use of environmentally harmful greases and oils. The aim of the current research was the development of a solid lubricant system with regenerative properties. The layer system consisted of a molybdenum (Mo) reservoir and a top layer of molybdenum trioxide (MoO₃). After surface wear, Mo is supposed to react with atmospheric oxygen and form a new oxide. The determination of the wear volume of thin layers cannot be measured microscopically, which is why the wear behavior is initially determined on the nano level. In this work, single Mo and MoO₃ coatings prepared by physical vapor deposition (PVD) are characterized by nano testing. The main objective was to determine the wear volume of the single coatings using a newly developed method considering the initial topology. For this purpose, nano-wear tests with different wear paths and normal forces were carried out and measured by in situ scanning probe microscopy (SPM). Based on the characteristic values determined, the coefficient of wear was determined for wear modeling according to Sarkar. The validation of the wear model developed was carried out by further wear tests on the respective mono layers.

Spark plasma sintering (SPS) or the field-assisted sintering technique (FAST) is commonly used to process powders that are difficult to consolidate, more efficiently than in the conventional powder metallurgy process route. During the process, holding time and applied holding pressure influence the product’s microstructure and subsequently its properties. In this study, in addition to the temperature impact, the influence of pressure and dwell time on the consolidation behaviour of titanium aluminide (TiAl) powders during the SPS process is investigated. Commercially available pre-alloyed TiAl48-2Cr-2Nb (GE48) and TiAl44-4Nb-0.7Mo-0.1B (TNM) powders were used, which have a high application potential in, for example, the aerospace industry. The results were evaluated based on microstructural analyses, hardness measurements and relative density calculations. It was shown that the investigated parameters significantly influence the sintering results, especially in the low temperature range. Depending on the temperature field in the sample, complete sintering is not achieved if the dwell time is too short in combination with too low a pressure. Above a certain temperature, the impact of holding pressure and holding time is significantly lower.

As one of the oldest shaping manufacturing processes, forging and especially hot forging is characterized by extreme loads on the tool. The thermal load in particular is able to cause constant changes in the hardness of the surface layer, which in turn has a decisive influence on the numerical estimation of wear. Thus, also during numerical wear, modeling hardness changes need to be taken into account. Within the scope of this paper, a new implementation of a numerical wear model is presented, which, in addition to dynamic hardness models for the base material, can also take into account the properties of a nitride wear protection layer as a function of the wear depth. After a functional representation, the new model is applied to the wear calculation of a multi-stage industrial hot forging process. The applicability of the new implementation is validated by the evaluation of the occurring hardness, wear depths and the locally associated removal of the wear protection layer. Consecutively, a tool life calculation module based on the calculated wear depth is implemented and demonstrated. In general, a good agreement of the results is achieved, making the model suitable for detailed 2D as well as large 3D Finite Element calculations.