Synthesis, characterization, and evaluation of nickel catalysts on nanocrystalline CeO۲ promoted by K and Mn for medium-temperature shift reaction and hydrogen purification

چکیده مقاله

In this work mechanical alloying (MA) was used for coating low carbon steel with Ni, Al and Fe powder mixture. Milling was done for 2, 4, 8 and 12 h. After milling, coated samples were annealed at 550 °C for 2 h. Phase analysis and microstructure of formed coatings were studied via X-ray diffraction (XRD) method and scanning electron microscopy (SEM), respectively. Microhardness and corrosion behavior of coated samples were also investigated. The results showed that complete formation of iron aluminide and nickel aluminide is possible after enough mechanical alloying and subsequent annealing. According to SEM images, 8 h milling results in a coating with 65 μm thickness and without any cracks unlike 12 h milled sample. Microhardness and corrosion current density of low carbon steel was measured 200 HV and 5.49 × 10− 6 A/cm2 and improved to 930 HV and 3.16 × 10− 8 A/cm2, respectively for 8 h mechanically alloyed and annealed sample.