Formation of layer-shaped pores in TiC-Fe cermet by combustion synthesis

To study the formation of layer shaped pores in TiC Fe cermet, two Ti C Fe powder compacts containing Ti powders with two size ranges (< 44μm and 135～ 154μm ) respectively were ignited in a special ignition mode. The combustion temperatures of the reactions were measured, the phase constituents of the combustion synthesized products were inspected by X ray diffractometry (XRD), and the structures of the products were observed with scanning electron microscope (SEM). In the case of the finer Ti powder used, TiC Fe cermet and pore rank in an alternately laminar shape, and the shape of the pore is the same as that of the combustion wavefront, implying that the layer shaped pore results from a gather of the retained gas into the combustion wavefront. While in the case of the coarser Ti powder used, the lower combustion temperature causes the gather of the retained gas to be difficult, the pore being present in an arbitrary shape and distributing randomly.

To study the formation of layer-shaped pores in TiC-Fe cermet, two Ti-C-Fe powder compacts containing Ti powders with two size ranges (< 44 mum and 135 similar to 154 mum) respectively were ignited in a special ignition mode. The combustion temperatures of the reactions were measured, the phase constituents of the combustion-synthesized products were inspected by X-ray diffractometry (XRD), and the structures of the products were observed with scanning electron microscope (SEM). In the case of the finer Ti powder used, TiC-Fe cermet and pore rank in an alternately laminar shape, and the shape of the pore is the same as that of the combustion wavefront, implying that the layer-shaped pore results from a gather of the retained gas into the combustion wavefront. While in the case of the coarser Ti powder used, the lower combustion temperature causes the gather of the retained gas to be difficult, the pore being present in an arbitrary shape and distributing randomly.