Method for making a porous sintered material

摘要

The invention provides a method for making a novel porous sintered material according to an HIP (Hot Isostatic Press) molding technique usually used for the purpose of obtaining defect-free and highly dense powder products. In the method of the invention, a capsule containing a starting powder in a hermetically sealed condition is heated according to a predetermined temperature pattern and is also subjected to hot isostatic pressing while a pressure is arrived at a maximum pressure level substantially in coincidence with commencement of a sintering temperature-applying period in the temperature pattern and is gradually lowered from the maximum pressure level during the sintering temperature-applying period. By the method, excessive densification is suppressed and the resulting sintered material has a required porosity and is provided with pores open to outside in the inside thereof, along with good strength and surface processability.