Porous Metal Bond Matrix with High Porosity and Large Pore Size Fabricated Using Pore-Forming Agent

Abstract

In order to improve the machining performance of the new type porous metal bond wheel, a new attempt were carried out for fabricating porous metal bond matrix with adjustable and high porosity as well as large pore size by use of pore-forming agent ammonium bicarbonate (NH4HCO3) and a vacuum loose powder sintering process. The porosity, bending strength and microstructure of the as-sintered porous metal bond matrix have been studied. The results show that the pore-forming agent NH4HCO3 with a certain amount can effectively increase porosity and pore size. The porosity of the fabricated porous metal bond matrix increases linearly with addition of ammonium bicarbonate and reaches as high as 67.7%, while the size of pores is larger than 300 μm. Meanwhile, the use of the raw materials were given and the sintering mechanism was discussed.