GRANULATlON PROCESS IN MAKING Ti-32Mo POROUS MATERIALS

The granulation process in Ti-32Mo porous materials made by P/M elements mixing method was described in the paper. In order to obtain excellent filtration properties of Ti-32Mo porous material made from fine Ti and Mo powder, a new granulation process was put forward.The Ti and Mo powders in proportion of 68:32 were well mined and followed by adding a litlle alcohol and mixed homogeneously.The mixed powders were rolled into green strip the thickness of which is lmm by using φ200 roll mill.The green strip was presintered in the vacuum furnace at 500~550℃ for 1 hour.Then the presintered strip was pulverized and classified.The presintered granular powder was forthes sintered in vacuum furnace at 1050℃ for 3 hours and then crashed and classified. The granular powder was used for making Ti-32Mo porous material.The granular particales obtained by using above new process possess enough strength, so that they will not be crushed and will remain their original shape and size during the forming process.The apparent density of granular powdes is 1.62~1.68 g/cm³ and the flow rate is 54~66.8 s/50g. Results obtained from investigation show that the Ti-32Mo alloy sintered filters made by this process have an improved air permeability coefficient which is three times higher of filters which were only sintered at low temperature in vacuum and higher than that of filters made by sponge Ti powder under the condition of same pore size, and even one time higher under the condition of big pore size.This granulation process can also be widely used for producing P/M porous materials by using other fine powders, such as w, Mo, Ti, Zr, etc.