Comparative Study of Experimental Methods for Measuring Thermal Properties of 100Cr6 Steel Powders

Powder materials are critical to numerous industrial applications, particularly in powder-based additive manufacturing. Their thermal properties directly influence the building process and, consequently, the dimensional accuracy and surface quality of the fabricated components. The measurement of the thermal conductivity and diffusivity of powders poses significant challenges due to their low conductivity in combination with restrictions when using containers as sample holder. This work introduces two new methods for characterizing the thermal properties of metallic powders, the temperature gradient method and the finite laser pulse response method. To assess these methods, 100Cr6 bulk and powder materials are characterized and compared to traditional laser flash analysis over a temperature range of 400–800 K. The thermal conductivity of the powder is about two orders of magnitude lower than that of the bulk material, with the measured value agreeing well with literature data. The study also documents changes in the microstructures of 100Cr6 bulk and powder materials before and after measurement, emphasizing the need to measure powder properties with efficient methods.