Kinetics of healing of pores on welded surfaces

Composition of contact zones and structural changes in a near-weld region of zone-refined iron and molybdenum monocrystals joined under different conditions without melting are considered. It is revealed that there exist optimal conditions of welding in a solid state including optimal temperatures. It is explained by the fact that the rate of pore healing at the joint boundary is essentially higher in an imperfect structure (before recrystallization). Motion rate of pore boundary is also determined by the degree of surface perfection. Less perfect surfaces move faster that results in growth of large plane pores