An improved wax based multi component binder and a new debinding method termed high pressure condensed solvent extraction were developed for powder injection molding of tungsten cemented carbide. The results indicate ...An improved wax based multi component binder and a new debinding method termed high pressure condensed solvent extraction were developed for powder injection molding of tungsten cemented carbide. The results indicate that a critical powder loading of 65% (volume fraction) and an ideal rheological properties were obtained by the feedstock based on the binder. High debinding rate and specimens with high strength were obtained by the debinding method. Moreover, by making high temperature holding time adjustable, it makes the subsequent thermal degradation process more flexible to debinding atmosphere and carbon content of the as debinded specimens controllable. The transverse rupture strength, hardness and density of the as sintered specimens made by an optimized PIM process are 2.48 GPa, HRA90 and 14.72 g/cm 3, respectively. Good shape retention and about 0.02% dimension deviation were achieved.展开更多
An improved wax-based binder was developed for the powder injection molding (PIM) of WC-TiC-Co cemented carbides. The critical powder loading and the rheologic behavior of the feedstock were determined. It was found t...An improved wax-based binder was developed for the powder injection molding (PIM) of WC-TiC-Co cemented carbides. The critical powder loading and the rheologic behavior of the feedstock were determined. It was found that the critical powder loading could achieve up to 62.5% (volume fraction) and the feedstock exhibited a pseudo-plastic flow behavior. The injection molding, debinding and sintering processes were studied. The dimension deviation of the sintered samples could be controlled in the range of ±0.2% with the optimized processing parameters and the mechanical properties were better than or equivalent to those of the same alloy made by conventional press-sintering process.展开更多
An improved wax-based binder was developed for the powder injection molding(PIM) of WC-TiC-Co cemented carbides. The critical powder loading and the rheologic behavior of thefeedstock were determined. It was found tha...An improved wax-based binder was developed for the powder injection molding(PIM) of WC-TiC-Co cemented carbides. The critical powder loading and the rheologic behavior of thefeedstock were determined. It was found that the critical powder loading could achieve up to 62.5percent (volume fraction) and the feedstock exhibited a pseudo-plastic flow behavior. The injectionmolding, debinding and sintering processes were studied. The dimension deviation of the sinteredsamples could be controlled in the range of + -0.2 percent with the optimized processing parametersand the mechanical properties were better than or equivalent to those of the same alloy made byconventional press-sintering process.展开更多
文摘An improved wax based multi component binder and a new debinding method termed high pressure condensed solvent extraction were developed for powder injection molding of tungsten cemented carbide. The results indicate that a critical powder loading of 65% (volume fraction) and an ideal rheological properties were obtained by the feedstock based on the binder. High debinding rate and specimens with high strength were obtained by the debinding method. Moreover, by making high temperature holding time adjustable, it makes the subsequent thermal degradation process more flexible to debinding atmosphere and carbon content of the as debinded specimens controllable. The transverse rupture strength, hardness and density of the as sintered specimens made by an optimized PIM process are 2.48 GPa, HRA90 and 14.72 g/cm 3, respectively. Good shape retention and about 0.02% dimension deviation were achieved.
文摘An improved wax-based binder was developed for the powder injection molding (PIM) of WC-TiC-Co cemented carbides. The critical powder loading and the rheologic behavior of the feedstock were determined. It was found that the critical powder loading could achieve up to 62.5% (volume fraction) and the feedstock exhibited a pseudo-plastic flow behavior. The injection molding, debinding and sintering processes were studied. The dimension deviation of the sintered samples could be controlled in the range of ±0.2% with the optimized processing parameters and the mechanical properties were better than or equivalent to those of the same alloy made by conventional press-sintering process.
基金This work was financially supported by the National Natural Science Foundation of China (No.50025412, 50274014), National 863 Program (No.2001AA337050) and National 973 Program (No.TG200067203)
文摘An improved wax-based binder was developed for the powder injection molding(PIM) of WC-TiC-Co cemented carbides. The critical powder loading and the rheologic behavior of thefeedstock were determined. It was found that the critical powder loading could achieve up to 62.5percent (volume fraction) and the feedstock exhibited a pseudo-plastic flow behavior. The injectionmolding, debinding and sintering processes were studied. The dimension deviation of the sinteredsamples could be controlled in the range of + -0.2 percent with the optimized processing parametersand the mechanical properties were better than or equivalent to those of the same alloy made byconventional press-sintering process.
