梯度孔结构泡沫镍铬合金滤管的制备及性能

以聚氨酯泡沫为前驱体,使用气雾化Ni-20Cr粉末为原料配制水基浆料,采用有机泡沫浸渍工艺制备了具有梯度孔结构的泡沫Ni-20Cr合金滤管。研究了不同烧结温度和装填方式对泡沫金属滤管烧结效果及力学性能的影响,并测试了烧结后泡沫滤管的力学性能和透气性能。结果表明:泡沫素坯经低温预烧+高温烧结的两步烧结工艺后可得到收缩均匀的泡沫合金滤管,孔筋结构均匀、无堵孔且复合界面结合良好。其室温压缩屈服强度大于3 MPa,且随着挂浆量的增加其屈服强度可达4.43 MPa;由于泡沫合金滤管高的孔隙率和大的孔径,且孔结构呈梯度变化,其在气体流量相同的情况下压差明显小于传统粉末冶金烧结多孔管。

Preparation and Performance of Ni-20Cr Foam Filter with Gradient Pore Structure

The Ni-20Cr foam filter with gradient pore structure was prepared by impregnating using polyurethane foams as templates. The effects of sintering temperature and loading mode on mechanical properties of Ni-Cr foam were studied. Also mechanical property and gas permeability of two-step sintered Ni-Cr foam filter were tested. The results show that Ni-Cr foam filter with gradient pore structure can be obtained after two-step sintering. The Ni-Cr foam has a reticulated structure composed of open, interconnected pores and uniform framework structure as well as good bonding at gradient pore interface. The yield strength of such foam is above 3 MPa, and with the increase of coating amount it could reach to 4.43 MPa. Due to higher porosity, bigger pore size and gradient pore structure, the differential pressure of Ni-Cr foam filter at the same gas flow rate is much less than that of traditional porous metal filter.