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Porous silicon carbide is a promising material for ceramic receivers in next-generation concentrated solar power receivers. To investigate its tolerance to thermal shock, accelerated ageing of large coupons (50 × 50 × 5 mm) was conducted in a solar furnace to investigate the effects of thermal cycling up to 1000 °C, with gradients of up to 22 °C/mm. Non-destructive characterization by computed X-ray tomography and ultrasonic inspection could detect cracking from thermal stresses, and this informed the preparation of valid specimens for thermophysical characterization. The effect of thermal ageing on transient thermal properties, as a function of temperature, was investigated by using the light-flash method. The thermophysical properties were affected by increasing the severity of the ageing conditions; thermal diffusivity decreased by up to 10% and specific heat by up to 5%.

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The aim of this work was to discuss the suitability of the joining process called “RM‐Wrap” (RM = Refractory Metals, ie, Mo, Nb, Ta, Zr) as a pressure‐less and tailorable technique to join several different ceramics such as SiC, alumina, and mullite (3Al2O3.2SiO2). In the RM‐Wrap joining technique the refractory metal foil is used as a wrap containing one or more silicon foils. It is performed at 1450°C, under flowing argon, and the resulting joining materials are in situ formed composites made of refractory metal disilicides (MoSi2, NbSi2, TaSi2, or ZrSi2) embedded in a silicon‐rich matrix; their coefficient of thermal expansion has been calculated and the Laser Flash Method was used to measure the thermal diffusivity of one of them (MoSi2/Si) in 25°C‐1000°C range, then to calculate its thermal conductivity. All the obtained joints are uniform, continuous, and crack free. Some preliminary oxidation tests were carried out on all joints at 1100°C, 6 hours in air, giving unchanged morphology of the interface and the joining materials itself; the joint strength of RM‐Wrap joined SiC was measured at room temperature using three different mechanical tests: (a) single lap (SL), (b) single lap off‐set (SLO) and (c) torsion on hourglass‐shaped samples (THG) (on Mo‐wrap joined SiC).

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