This paper discusses an MHD generation channel wall that is made of refractory ceramics. Authors have invented a channel wall that has buffer layers between wall elements and holders. This buffer layer has an important role for avoiding fracture of the element by thermal stress which occurs from restriction of thermal deformation of the element. A wall model is composed for obtaining the thermal resistance of the buffer layer. A buffer layer of the model is consisted to an adhesive layer and a buffer body. The adhesive layer is made of a copper plate, which is 0.3mm thick, and adhered to the element by Refractory Method. The adhesive layer is consisted to three layers, i.e., Cu, Cu2O and CuO. These three layers seems to give rise to the thermal resistance. The buffer body is made of nickel wires of which radious is 0.4mm and purity is 99.7%. All of the nickel wires are assembled in one direction which is parallel to a center line of the element, and bundled all together. Occupation ratio of nickel is about 78% in a sectional area of the buffer body. One end of the buffer body is soldered to adhesive layer by silver solder and opposite end is soldered to holder by lead solder. An element of the model is made of magnesia ceramics of which purity is about 99.9% and porosity is about 3%. A holder of the model is made of copper block. Results are as follows:
(1) Thermal resistance of the buffer layer is from 1.9 to 2.5K/(W/cm2).
(2) Thermal resistance of the adhesive layer is from 0.43 to 0.87K/(W/cm2).
(3) Thermal resistance of the buffer body is calculated to about 0.7K/(W/cm2) under the estimation at which the heat flows in the nickel wires only.
(4) From above results, thermal resistance of silver soldering layer seems to be same as that of the adhesive layers.
The buffer layer needs more value of the thermal resistance in order to apply to the MHD generation channel. Value of the thermal resistance is easily satisfied by changing of material of the buffer body, increase of thickness of the buffer layer and etc. Then this wall appears to be useful to an MHD generation channel wall.