Ni-Cr-Fe多孔材料的制备及抗氧化性能

Fabrication and high temperature oxidation resistance of porous Ni-Cr-Fe alloys

采用元素粉末反应合成法,利用固相偏扩散的原理进行固相烧结制备Ni-Cr-Fe多孔材料。通过表征多孔材料在不同烧结温度下的膨胀率、孔结构变化及物相组成研究材料的成孔过程,探讨造孔机理;并研究Ni-Cr-Fe多孔材料在1000℃下的高温抗氧化性能。结果表明:Ni-Cr-Fe在1380℃下达到最大膨胀,最大径向膨胀率达7%,开孔隙率为32.5%;最大孔径与透气度分别为90μm和990 m^3/(m^2·k Pa·h)。Cr、Fe元素向Ni元素的偏扩散形成大量丰富孔隙。在氧化实验中,在1000℃高温下氧化560 h后多孔Ni-Cr-Fe最大孔径及透气度变化不大,而同等条件下氧化的Ni-Fe、Ni-Cr多孔材料孔结构变化较明显,表明Ni-Cr-Fe多孔材料具有优异的高温抗氧化性能。

The porous Ni-Cr-Fe alloys were prepared by reactive powder synthesis method, which used the principle of partial diffusion in solid phase sintering. The expansion rate, changes of pore structure and phase composition of porous Ni-Cr-Fe alloys under different sintering temperatures were characterized to research the pore forming process and explore the mechanism of pore. And the high temperature oxidation resistance of porous Ni-Cr-Fe alloys at 1000 ℃ was studied. The results show that the radial direction expansion has the largest value after being sintered at 1380 ℃ and the values is 7%. The open porosity of the materials is 32.5%, the maximum pore size and the permeability of the materials are 90 μm and 990 m^3/(m^2·k Pa·h), respectively. The large amounts of pores form due to the partial diffusion of Cr and Fe elements into Ni. In the oxidation experiments, the maximum pore size and permeability of Ni-Fe and Ni-Cr with oxidation for 560 h change more obviously than those of Ni-Cr-Fe porous material under the same conditions which indicates that Ni-Cr-Fe porous alloys have excellent high temperature oxidation resistance.