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Today, there is a high demand and increasing trend for multifunctional composite materials and components due to the combination of a wide range of favorable properties. However, undesired deformation leading to delamination, curvature, cracks, or even complete fracture frequently occurs during the co‐sintering process of metal–ceramic laminates (MCLs). To solve these issues, experimental work highly relies on the time‐consuming trial‐and‐error principle. This work aims to develop a thermo‐mechanical‐metallurgical model capable of predicting the densification, deformation, and delamination of MCLs during the co‐sintering process. It is found that the developed model successfully considers the inhomogeneous relative density distribution and phase transformation of the steel tape. In addition, a thin interlayer formed by a mixed slurry in the MCLs is modeled as cohesive elements to simulate the delamination process. The developed model is systematically validated by the experimental measurements and observations in terms of densification, deformation, and delamination during the co‐sintering process of the investigated laminate variants. [ABSTRACT FROM AUTHOR]

Reactive Air Brazing (RAB) enables the joining of vacuum-sensitive oxide ceramics, such as Ba0.5Sr0.5Co0.8Fe0.2O3−δ (BSCF), to metals in a one-step process. However, damage may form in ceramic or joint during RAB. In this work, experimental microstructure characterization, measurement, and prediction of local material properties using finite element analysis were combined to enlighten these damage mechanisms, which are currently not well understood. Micromechanical simulations were performed using representative volume elements. Cooling simulations indicate that small-sized CuO precipitations are most likely to cause crack initiation in BSCF during cooling. The ball-on-three-balls experiment with porous BSCF samples was analyzed numerically to determine the values of temperature-dependent BSCF fracture stresses. The inversely calibrated fracture stresses in the bulk BSCF phase are underestimated, and true values should be quite high, according to an extreme value analysis of pore diameters. [ABSTRACT FROM AUTHOR]

Additive manufacturing by laser‐based powder bed fusion of metals (PBF‐LB/M) enables the production of complex shaped components. High‐carbon tool steels tend to cracking during PBF‐LB/M due to internal stresses caused by the rapid solidification. Expensive atomization and long lead times for powder generate high costs in this processing route. In situ alloying during PBF‐LB/M of powder blends from conventionally available powders enables a more flexible approach of alloy design. For industrial use, the mechanical properties of in situ alloyed parts must be comparable to those of conventionally manufactured parts. In some cutting and forming applications, high wear resistance and corrosion resistance are required simultaneously. High alloyed cold work tool steels with sufficient chromium solved in the metal matrix fulfill these demands. Herein, AISI H13 is modified by Cr3C2 and elemental Cr to suit these requirements. Two novel alloys are modeled thermodynamically and processed by PBF‐LB/M. In‐depth microstructural investigations by backscatter electron imaging and diffraction in combination with abrasive wear tests and potentiodynamic polarization curves allow microstructure property correlations for different heat‐treated conditions. Partial crack‐free processing, hardenability, formation of Cr‐rich carbides, and residual Cr‐rich inclusions are observed and their influence on the wear and corrosion resistance is discussed. [ABSTRACT FROM AUTHOR]

Laser additive manufacturing enables the one‐step fabrication of complex parts. However, pores and carbide networks, which are not avoidable from the laser powder‐bed fusion (LPBF) process, deteriorate the fatigue strength significantly. Hot isostatic pressing (HIP) with integrated heat treatment is a powerful post‐treatment that densifies the material and modifies the microstructure. Herein, AISI M3:2 samples are produced by LPBF and then are either austenitized, quenched, and tempered in a HIP unit under pressure or are only hardened and tempered in a vacuum oven. The corresponding microstructure is analyzed by optical microscopy, scanning electron microscopy using energy‐dispersive X‐ray spectroscopy, and X‐ray diffraction. The fatigue strength is determined by rotation bending tests. Fracture surfaces are observed under scanning electron microscopy for failure analysis. While both post‐treatments lead to similar microstructure, the fatigue strength is significantly improved by the HIP process. [ABSTRACT FROM AUTHOR]

In this study, the microstructure and mechanical properties of martensitic hot-work tool steel AISI H13 produced by laser powder bed fusion (LPBF) under argon atmosphere in different LPBF process times were analysed in the as-built, hardened and tempered (HT) and hot isostatic pressed, hardened and tempered (HIP+HT) condition and compared to conventionally manufactured reference material. Three parameter sets were selected to adjust an initial defect density of 0.6%, 0.9% and 2.2% and thus process time reductions of 17% and 29%. We observed a change in the defect type from almost argon-free microcracks to argon-filled pores with higher scan velocities. Argon embrittlement was evident also in the results of tensile, notched impact toughness and fatigue tests. After HIP+HT a fatigue strength of 972 MPa was obtained for the set with 0.6% microcracks, but only 775 MPa and 718 MPa were obtained for samples with argon porosity. [ABSTRACT FROM AUTHOR]

Tool steels are known to be difficult to process by laser powder bed fusion as they were not designed to fit the welding or additive manufacturing (AM) process route. Hot cracks and cold cracks are known to occur in such alloys. To gain insights on limits of alloying contents regarding primary carbides in the melt, powder blends based on AISI H13 with additions of Cr3C2 carbides are processed by laser powder bed alloying (LPBA) herein. The LPBA process is evaluated based on demixing phenomena observed in the macroscopic chemical composition of the specimen. In‐depth microstructural analyses are carried out to understand the metallurgical behavior of the new alloy and are accompanied by Calphad modelling. Hardness tests characterize the alloy's suitability as a novel tool steel. The alloy's hot cracking tendency is reduced by systematic additions of Cr3C2 to AISI H13 which narrow the solidification interval. Hardness tests after martensitic hardening without annealing have shown the applicability of the new alloy as AM tool steel. Apparent chemical gradients over the build plate demonstrate that further research is needed to improve the technology of LPBA for processing these novel alloys. [ABSTRACT FROM AUTHOR]