Metal binder jetting is a high throughput additive manufacturing process of growing interest. The progress is driven by improvements in machine technology, enabling the processing of finer powders to produce homogeneous, dense final parts. However, the strong cohesive forces of fine metal powders impair flowability, packing behaviour and thus the properties relevant for powder spreading. This paper investigates the impact of powder condition and spreading parameters on green and sintered density using an Analysis of Variance. Parts from dried and from untreated powder are printed, varying in layer thickness, roller diameter, supply-to-spread ratio, translational and rotational roller speed. Powder drying increases the statistical impact of the spreading parameter and improves the green density, while the sintered density remains unchanged. Layer thickness and roller diameter have the most significant effect. Furthermore, the spreading parameter combinations that resulted in a high green density also provided a high sintered density.

In recent years, magnetocaloric materials have been extensively studied as materials for use in alternative cooling systems. Shaping the magnetocaloric material to thin-walled heat exchanger structures is an important step to achieve efficient magnetocaloric cooling systems. In the present work, experimental investigations were carried out on the heat treatment of LaFe_11.4Si_1.2Co_0.4 alloy processed by Laser Beam Melting (LBM) technology. Due to the rapid solidification after melting, LBM results in a refined micro structure, which requires much shorter heat treatment to achieve a high percentage of magnetocaloric 1:13 phase compared to conventional cast material. The influence of the heat treatment parameters (temperature, time, and cooling rate) on the resulting microstructure has been extensively studied. In addition to the conventional heat treatment process, induction technology was investigated and the results were very promising in terms of achieving good magnetocaloric properties after short-time annealing. After only 15 min holding time at 1373 K, the magnetic entropy change (∆S) of -7.9 J/kg/K (0–2 T) was achieved.

The combination of Additive Manufacturing (AM) and Hot Isostatic Pressing (HIP) offers great potential for industrial applications. Skilfully connecting AM and HIP creates a manufacturing process that unites the advantages of the two approaches. We demonstrate a production route for composite components by combining AM and HIP: a HIP capsule made of corrosion resistant steel is additively manufactured using Powder Bed Fusion with Laser Beam (LPBF). Before LPBF, the distortion and shrinkage of the capsule due to HIP is compensated by optimising the capsule’s geometry using Finite Element (FE) simulation of the HIP process. The capsule is filled with steel powder and manufactured by a conventional powder HIP. After HIP, the capsule remains as an outer layer on the component, so that a functional net-shape composite component is produced. Subsequent investigations show that a complex extruder screw segment can be successfully produced with a geometrical deviation smaller than 1.5%.

The sintering behaviour of LaFe_11.0Si_1.2Co_0.8 powder produced by gas atomisation was examined to provide a basis for the application of powder metallurgical shaping technologies to magnetocaloric La(Fe,Si)₁₃-alloys. The aim was to establish sintering parameters for attaining both high densification and good magnetocaloric properties for the investigated particle sizes <10 µm and <25 µm. Dilatometry measurements and sintering trials were carried out and density, microstructure and entropy change ΔS of the sintered samples were analysed. For the fine particles <10 µm, the lowest investigated sintering temperature 1150°C results in a relative density of 97%, a low α-Fe content and a high ΔS = −5 J kg⁻¹ K⁻¹ (ΔH=2 T). For powder <25 µm, a two-stage process is required to achieve similar properties.