Synthesis of Intermetallic Compounds in the Ni-Cr-Si System by Mechanical Alloying and Spark Plasma Sintering
The purpose of this study is to find out the intermetallic composition of Ni-Cr-Si nanostructures and investigate their formation mechanism during mechanical alloying (MA) and spark plasma sintering (SPS). In this study, Ni (50 wt%), Cr (25 wt%), and Si (25 wt%) were mixed and mechanically alloyed by a planetary ball mill. X-ray diffraction (XRD) test was used to examine the structural changes of the powder particles during mechanical alloying. The morphology and the microstructure of the powder particles were characterized by scanning electron microscopy (SEM). The results showed the formation of two nanocrystalline Ni(Si) and Cr(Si) solid solutions after 70 hours of milling. Then, the resulting powder was sintered by spark plasma sintering (SPS) technique and XRD and SEM were used to examine the structural changes and phase transformations of bulk sample. XRD result showed that three intermetallic compounds (Ni31Si12, Cr6.5Ni2.5Si, and Cr3Ni5Si2) were conducted. Porosity and hardness of the bulk sample were measured. The microhardness value and volumetric porosity of the sintered sample were reported as 973±39.7 kg/mm2 and 8%, respectively.
Keywords: Nanocrystalline, Mechanical Alloying, Ni-Cr-Si, Intermetallic compounds
Citation: Tavakoli R, Enayati M.H “Synthesis of Intermetallic Compounds in the Ni-Cr-Si System by Mechanical Alloying and Spark Plasma Sintering”. SVOA Materials Science &Technology, 2021, 3(3) Pages: 45-50.
