Abstract
Carbon brush block is a product of powder material pressed into form and burnt. Naturally it is not perfectly homogeneous but considerably heterogeneous. Investigation should be made therefore into the degree of heterogeneity and the possible regularity governing the heterogeneity. Experimental results show that the upper surface of the same piece of block has higher values of Young's modulus and tensile strength than the lower one; the edges give higher values of these than the centre; in Young's modulus the sides are superior to the pressed surfaces, while in tensile strength, the former is inferior to the latter.
If these facts are fully studied, the results will contribute to the clarification of the inner structure of carbon brush block.
