Abstract
A new production process of sintered hollow high speed tool steel bar blanks by binder-assisted powder extrusion method has been developed. This technology is mainly applied to produce hollow bar blanks for oil hole drills, taps and punches. Further it is applicable to produce highly alloyed solid bar blanks which are not able to be produced by hot forging or rolling. Materials made by this process show virtually full density only by sintering and their microstructures are as fine as gas atomized and HIP processed materials. Mechanical properties of these materials are almost as same as those of gas atomized and HIP processed materials because of their fine mictostructures.
The cutting performance of AISI T15 oil hole drills made of the sintered hollow blanks showed approximately 1.5 times better than that of conventionally processed AISI M 2 oil hole drill.
The optimum powder characteristics for binder-assisted powder extrusion and properties of sintered blanks by this process are reported.
