本文透過無壓式粉末冶金法製備多孔合金，製備了具有孔徑1.8 mm和孔隙率51%的多孔Fe-4Ni-0.6C-(0.5Mo)合金；並透過合金微結構和機械性質分析，探討添加微量鉬(0.5 wt%)及不同熱處理條件(高溫及低溫回火和深冷處理)對其性質的影響。未含鉬的多孔合金，經深冷處理後，在低溫(200 ℃)回火時，因析出較多的過渡碳化物(ε/η)，使其能在回火後有效提升壓縮性質。並在高溫(500 ℃)回火時，雖壓縮性質相對較低，但與未經深冷處理的合金相比，均有較高的壓縮平台應力和能量吸收值，主要原因為球狀雪明碳鐵的細化。這些研究結果顯示，深冷處理可以有效改善多孔合金的壓縮性質，為開發高強度吸能材料提供了有益的參考。 結果顯示，經淬火深冷後含鉬的多孔合金，在低溫(200 ℃)回火時，壓縮平台應力達到了459 MPa，單位能量吸收值更達到了60 J/g，因其合金微結構保有高硬度的回火麻田散鐵。此外，在相同的熱處理條件下，相較於未含鉬的合金，含鉬的合金展現出更高的壓縮平台應力和能量吸收值，鉬的添加能有效提升合金的壓縮性能。;This study investigates the production of Fe-4Ni-0.6C-(0.5Mo) metal foams utilizing a pressureless powder space holder technique, resulting in materials with a 1.8 mm pore size and 51% porosity. The impact of Mo (0.5 wt%) incorporation and different heat treatment processes (such as tempering and cryogenic treatment) on the microstructural changes and mechanical characteristics of the foams was thoroughly examined. In the absence of Mo in the metal foams, cryogenic treatment followed by tempering at low temperature (200 °C) induced the formation of a higher volume fraction of transition carbides (ε/η), leading to improved compressive properties. While high-temperature tempering (500 °C) slightly decreased the compressive attributes, the carbide precipitates in the cryogenically treated foam were finer than those in the untreated foam, resulting in significantly higher compressive plateau stress and energy absorption values. The findings underscore the effectiveness of cryogenic treatment in enhancing the compressive properties of metal foams, offering valuable insights for creating high-strength, energy-absorbing materials. In addition, the Mo-inclusive metal foams, after quenching and cryogenic treatment, preserved high-hardness martensite during low-temperature tempering (200 °C), achieving an impressive compressive plateau stress of 459 MPa and energy absorption capacity of 60 J/g. Moreover, when compared to Mo-free counterparts under the same heat treatment conditions, the Mo-containing metal foams exhibited superior compressive plateau stress and energy absorption capacity, demonstrating the advantageous impact of Mo addition in enhancing the compressive performance of the foams.
