High-performance cutting materials are central to modern production engineering. Cemented carbides dominate industrial tooling, while polycrystalline boron nitride (PcBN) is established for hard turning and finishing nickel-based alloys. The associated tool manufacturing chains are energy- and effort-intensive, motivating approaches that reduce material losses and primary energy demand. This study quantifies energy consumption across the production of solid carbide cutting tools with a focus on near-net-shape green machining, its impact on subsequent grinding and material recirculation. It also quantifies energy consumption for regrinding PcBN cutting tools. Power measurements were recorded during green machining and tool grinding of cylindrical versus pre-contoured (green-machined) blanks, including coolant units for the carbide tools during operation. Tool performance of the carbide tools was assessed via milling tests in 42CrMo4; PcBN reground tools were evaluated in Inconel 718. In the process chain of carbide tool production, specific energy decreased from 6.98 to 6.36 kWh/kg (−8.88%) despite +0.461 kWh/kg for green machining; direct recirculation of green-machined material saved an additional 5.861 kWh/kg. Reground PcBN inserts achieved comparable tool life to new tools while reducing energy by ≈85% per insert. The dominant levers for energy reduction are shorter grinding times in the presence of high machine and coolant base loads and systematic regrinding of high-embodied-energy tools.

This study introduces a newly developed experimental setup for investigating the influence of controlled atmospheric conditions on single-grain scratching of Ti-6Al-4V using natural diamond grains. The setup enables experiments under air, argon, and argon-silane atmospheres, allowing targeted investigation of oxygen-related effects on material removal. High-speed imaging captures chip formation and chip-grain interactions during the process, while scanning electron microscopy and metallographic analysis provide complementary information on grain condition and material adhesion. Validation experiments demonstrate reliable and repeatable scratching under oxygen-reduced and oxygen-free conditions. Within the investigated parameter range, the measured normal and tangential forces show no clearly distinguishable systematic dependence on atmosphere, although potential effects may be masked by variations in grain geometry and effective depth of cut. In contrast, pronounced differences in chip adhesion behavior are observed. In ambient air, rapid chip detachment is promoted, associated with formation of a thin passivating titanium oxide layer. Under oxygen-reduced conditions, suppressed oxidation leads to increased adhesion and local material accumulation on the grain. Overall, the results confirm the suitability of the methodology for in situ investigation of atmosphere-dependent mechanisms and provide a foundation for future studies on oxygen effects in grinding and related machining processes.

To maximize the wear resistance of high-performance cutting tools, hard coatings are applied by using Physical Vapor Deposition (PVD). Beyond the specific cutting conditions, the coating composition and the resulting coating properties are decisive factors influencing the performance of the cutting tool. This paper investigates the effects of different functional layers and the resultant coating properties on the wear behavior of the cutting tools during turning of C45+N steel. Therefore, cutting tools based on WC-Co substrate with 6 wt.% Co are coated with TiAlCrN, TiAlSiN, and TiAlCrSiN. A comprehensive coating characterization was conducted, including the measurement of residual stresses by focused ion beam combined with digital image correlation. The coated tools were used in turning experiments to determine the tool wear behavior of the different coatings. Among the coatings the TiAlCrN coating demonstrated the longest tool life. This study aims to establish a connection between coating properties with a focus on the residual stresses and wear behavior of different coating compositions.

PVD coatings with high wear resistance are commonly applied to protect cutting tools from wear under high thermomechanical loads during cutting processes. In this study, the influence of cobalt content in cemented carbide (WC/Co) substrates and the interlayer thickness in a TiAlCrN coating system on tool wear and thermomechanical load is investigated. TiAlCrN PVD coatings with three different interlayer thicknesses were applied to WC/Co substrates with two different Co contents. The coating properties of these six coating-substrate systems were first determined. The coated cutting tools were then subjected to turning experiments to evaluate tool wear of the six coating-substrate systems. Using coating properties and the collected data from the cutting experiments, the thermomechanical load of the tool was simulated by means of finite element (FE) simulation. The simulation shows that the stresses in the tool are higher with increased Co content. The simulation results align with the findings from the turning experiments and will be used in further studies as a whitebox-model (FE simulation) in a greybox approach (model combining FE simulation and data-driven machine learning method).

Knowledge of thermal tool loads is essential for the design of cutting fluid supply strategies. An in-situ thermography-based method is presented for measuring temperature distributions at 1.9 µm/pixel and 670 Hz under cutting fluid pressures up to 80 bar. The method is validated by two-color pyrometry and finite element simulations, enabling analysis of the influence of cutting fluid supply on thermal tool loads and the energy efficiency of cutting processes. The investigations show that at a pressure of 45 bar and an adapted cutting fluid nozzle diameter lead to reduced thermal loads and minimized energy consumption of the pump.

ABSTRACT This paper lays the foundation for an inverse model to achieve tailored residual stress depth profiles in deep rolled Tailored Forming components. A sinusoidal decay function is employed to characterize residual stress depth profiles, with coefficients determined through regression analysis of empirical data. First, a forward model is created that can predict residual stress profiles for deep rolling parameters. The inverse modeling will be realized using a genetic algorithm, allowing for the determination of deep rolling parameters to achieve desired residual stress depth profiles. Validation of the forward model shows promising results in predicting residual stresses. This work contributes to the field of targeted residual stress engineering and has potential applications across various industries, including aerospace, automotive, and energy production.

Grinding is an energy-intensive manufacturing process, which converts a large part of energy into heat, possibly causing critical damage to the tool or workpiece. Therefore, energy-consuming cooling of the process is required. Currently efforts are being made to completely eliminate the use of metalworking fluid during grinding. Therefore, this paper investigates the influence of process parameters on the resulting surface and subsurface properties while dry grinding. It was shown that with suitable process control, constant compressive residual stresses can be induced in the subsurface, whereby the level of residual stresses is particularly influenced by the cutting speed as a result of the power input. A significant influence on the surface roughness was not observed. On average, the roughness values R10z were 3.2 µm and Ra 0.45 µm.In addition, the influence of an XHV-adequate atmosphere on the grinding process and the grinding result was investigated, as recent research results show positive effects on the friction behavior. In this case, constant compressive residual stresses were also applied in the subsurface. The resulting surface integrity was on average R10z = 4.67 µm and Ra = 0.79 µm and therefore higher than when grinding in air. There was also welding of chips under an XHV-adequate atmosphere.

Machining of steels for aerospace industry, such as 300M, is challenging due to the high ductility, hardness and tensile strength. During turning, long continuous chips usually form. These continuous chips decrease the process reliability. In addition, the workpiece surface can be damaged. Heat removal from the machining process is also impeded by inadequate chip flow. This leads to increased thermal loading on the tool and premature tool failure. The cooling strategy exhibits a crucial role in reducing these effects. This study investigates the effects of coolant pressure and concentration on tool wear, process forces and chip formation during turning. Experimental analyses show that coolant concentration and pressure influence tool life, while an optimal balance is required to prevent thermal overload. The results suggest that directed coolant nozzles and process-adapted pressures enable resource-efficient cooling strategies and also improve chip formation and chip breaking behavior.

The wear behaviour of cutting tools depends significantly on the mechanical load on the cutting wedge. The rake angle influences the chip formation and thus the mechanical loads. The influence on the shear angle, the contact length and the process forces was investigated. An experimentally based method was used to investigate the influence of the rake angle on the normal and tangential stresses on the cutting wedge when machining AISI4140.

The load‐bearing capacity and fatigue life of mechanically stressed titanium components are largely determined by surface and subsurface properties such as surface hardness and residual stresses. Titanium alloys have a high chemical affinity for oxygen. However, it is not yet known how the atmospheric oxygen present during cutting interacts with the resulting surface and subsurface properties. This study therefore investigates the influence of oxygen content on the resulting roughness of the workpiece surface, the microhardness of the workpiece surface, and the residual stresses during turning of Ti–6Al–4V as a function of the oxygen content of the ambient atmosphere. An innovative approach is the utilization of a gas mixture of argon and silane, which replaces the ambient air and thus creates an atmosphere that resembles an extremely high vacuum (XHV‐adequate) in terms of oxygen content. The results demonstrate that the oxygen content of the atmosphere does not influence surface roughness. However, the use of the XHV‐adequate atmosphere increases the surface hardness of the machined components by up to 7.8% compared to machining in air. Furthermore, the residual stresses of components manufactured in an XHV‐adequate atmosphere exhibit up to 287 MPa higher compressive residual stresses compared to components manufactured in air.

Grinding of Ti-6Al-4 V remains challenging due to low thermal conductivity, high chemical reactivity, and pronounced ductile deformation behavior. Existing research suggests that titanium oxide layers may influence grinding behavior by modifying interfacial interactions and material removal mechanisms. The experimental isolation of oxygen-related effects during grinding remains challenging, as conventional machining environments typically allow continuous oxidation of surfaces and chips. Within the research framework of the Collaborative Research Centre SFB 1368 “Oxygen-Free Production”, dry surface grinding of Ti-6Al-4 V is investigated under ambient air and strictly oxygen-free conditions using a gastight grinding setup that enables an XHV-adequate atmosphere with extremely low oxygen partial pressure. This approach allows oxygen-induced effects to be systematically suppressed and their influence on grinding behavior to be directly assessed. Process forces, surface topography, residual stresses, wheel loading, and chemical surface composition are analyzed using force measurements, optical surface measurement, X-ray diffraction, scanning electron microscopy, EDX and optical microscopy of metallographic cross-sections. The results show that grinding under oxygen-free conditions leads to increased wheel loading, higher and more unstable forces, wave-like surface topographies, elevated tensile residual stresses, and increased surface roughness. These effects are attributed to the absence of process-induced oxide formation, which promotes adhesion and shifts the process from cutting to being more friction-dominated. These findings demonstrate that oxidation during grinding plays a critical role in stabilizing material removal mechanisms in titanium grinding.

Grinding processes are governed by microscopic interactions between the workpiece, grinding wheel, and coolant. Even under constant process parameters, microscopic fluctuations in the contact zone cause variations in thermomechanical load and workpiece quality. While fully resolving these effects in simulations would improve process understanding, the computational cost is prohibitive. This article presents a multiscale simulation approach that incorporates local microscopic phenomena and uncertainties into an overall grinding process simulation. A microscale material removal simulation predicts local grain interactions, grinding forces, heat input, and surface topographies. These results are scaled to the macroscopic contact zone and used as inputs for a thermo-fluid model that computes flow profiles and temperature distributions in the workpiece, wheel, and coolant. The influence of cooling parameters and wheel condition is analysed and validated on a creep feed grinding process through comparison with experimental data and analytical models.

In conventional grinding processes, tools with deterministic abrasive grain arrangements can significantly reduce forces and temperatures compared to random distributions. New additive manufacturing processes enables to produce grinding segments with deterministic grain arrangements for diamond wire grinding. This study investigates the effect of deterministic abrasive grain arrangement on the performance of diamond wire tools for dry cut-off of steel. Two additively manufactured, sintered-bond wires with deterministic grain patterns were compared with an electroplated and a sintered wire with stochastic grain distributions. Performance was assessed by specific material removal rate A ' w , process forces, wire temperature, and vibration amplitude. Although they do not achieve the same material removal rate as the electroplated reference, the new tools offer clear advantages over random grain distribution. Among sintered tools, deterministic abrasive grain arrangement delivered higher material removal rate and less vibrations as well as increased the force ratio relative to the stochastic reference.

Galvanisch nickelgebundene Dentalschleifwerkzeuge sind mit Umwelt- und Gesundheitsrisiken verbunden. Im Forschungsprojekt „GreenDentalGrind“ wird daher eine nachhaltige Kupferbindung als Alternative entwickelt. Durch den Einsatz titanbeschichteter Diamantkörner und eine prozessintegrierte Wärmebehandlung zur Bildung von Titankarbid soll die Anbindung der Körner verbessert und eine vergleichbare Leistungsfähigkeit zu konventionellen Nickelsystemen erreicht werden.

Cooling time has a significant impact on efficiency, productivity, and sustainability in various applications. One innovative approach to improve cooling efficiency is the generation of turbulent flows in the cooling channels by a novel and function-oriented texturing of the channel wall surfaces, which enhances heat transfer. A predictive model was developed to understand the interdependence of surface topography and cooling channel topology on turbulent flow and cooling time reduction. The model uses a combination of material removal simulation for machining processes and CFD simulations for cooling behavior. Experimental validation of this approach confirms a 37% reduction in cooling time.

Grinding in conventional air atmospheres is affected by the formation of oxide and passivation layers, which alter friction, material removal behavior, and surface integrity. This study investigates the influence of an oxygen-free atmosphere on surface grinding by eliminating atmospheric oxygen through argon purging and the introduction of an Ar/SiH 4 gas mixture, achieving an extremely low oxygen partial pressure. Four materials with different oxygen affinities (Ti-6Al-4 V, AlSi10Mg, C45 steel, K40-UF) were machined under both air and oxygen-free conditions. Process forces, residual stresses, and surface roughness were evaluated to identify atmosphere-dependent effects. The oxygen-free atmosphere led to reduced normal grinding forces, most notably for the cemented carbide K40-UF, while tangential forces remained largely unchanged. Residual stresses shifted toward more favorable compressive levels for all materials except AlSi10Mg. Surface roughness parameters were mostly unaffected, with measurable changes in Svk and Sk only for Ti-6Al-4 V and minor variations for C45. The results indicate that oxygen suppression reduces friction and modifies surface interaction mechanisms, particularly under higher thermal loads. This study provides a systematic assessment of atmospheric oxygen as an influential process variable in grinding and highlights the material-dependent sensitivity of grinding mechanisms to oxygen-free conditions.

By influencing the properties of the surface and subsurface through deep rolling, the fatigue life of components can be significantly increased. However, this is largely dependent on the temperatures that occur during the process. To gain a deeper understanding of the thermal influence during hard turning, it is necessary to analyze the thermal influence decoupled from the machining process. For this reason, a method has been developed that allows the inductive heating of components to specifically study the influence of deep rolling at different temperatures. Based on simulations, the inductive heating of bearing rings was designed and implemented in a machine tool. The method allows targeted local and time-defined heating through knowledge of the coupling power and temperature control during inductive heating in a machine tool. Surface temperatures ranging from T O = 100 °C to 400 °C can be set.

High-performance cutting tools are exposed to high temperatures during use. Understanding the thermal influence on the coating and substrate properties is therefore key to predict the tool performance of PVD-coated tools. In machining tests, thermal and mechanical loads cannot be separated from each other. To investigate the influence of thermal load separately, the tools in this study, TiAlN-coated cemented carbides, were initially only subjected to thermal load. Its influence on the coating and substrate properties was then analysed. To understand the effect on cutting behaviour, both thermally loaded and reference tools were used in machining tests and their wear behaviour was analysed. With this approach, the effect of the thermal load itself on the coating and substrate properties could be isolated. On key finding is that the residual compressive stresses in the TiAlN coating were reduced. In addition, the cobalt concentration at the interface of the substrate was reduced as well. In wear investigation these pretempered tools featured an average 24 % reduced tool life compared to the reference tools.

This study presents a microscale tribological simulation model to investigate local friction conditions in the secondary shear zone during both dry and wet machining. The precise characterization of tool-chip interactions, particularly the influence of plastic deformation and metalworking fluids on friction, remains a challenge in machining research. To address this, a combined experimental and numerical approach was employed. Chip root surfaces were analyzed using laser scanning microscopy, while friction tests quantified the coefficient of friction of thermally formed reaction layers. The results show that these layer drastically influence the frictional behavior. The simulation model was developed in two stages. First, a solid contact model based on the Johnson-Cook plasticity model was used to represent plastic deformation under dry conditions. It was found that the coefficient of friction decreases with increasing contact pressure and temperature. Second, a coupled simulation approach was introduced to investigate the influence of metalworking fluids, demonstrating a transition from dry conditions to mixed lubrication at lower pressures. Below a pressure of 200 MPa, friction was substantially reduced, whereas above 600 MPa, the lubricant film failed, resulting in dry contact conditions. These findings emphasize the importance of considering both mechanical and thermal interactions when modeling friction in metal cutting. The simulation framework provides a basis for future research on thermal integration and multi-scale simulation of chip formation.

This study examines local friction behavior at the chip-tool interface in metal cutting by integrating chip formation and microscale contact simulations. This research examines the mechanical effects of high-pressure metalworking fluid (MWF) supply on chip formation, specifically its impact on frictional interactions at the tool-chip interface. Through finite element modeling and a microscale contact model, this study provides detailed insights into the effects of high-pressure MWFs on local friction coefficients, contact length, and pressure distribution in the secondary shear zone. Experimental validation using high-speed orthogonal cutting tests demonstrates strong agreement between simulated and observed results, confirming the effectiveness of the multi-scale model. The findings suggest that optimized high-pressure lubrication significantly enhances tool life, reduces process forces, and improves surface quality, making it a valuable strategy for advanced machining applications.