Experimental investgation and thermodynamic descriptions of the Ni-Si and C-Ni-Si systems

摘要

The binary Ni-Si phase diagram is reassessed anda consistent set of thermodynamic parameters is obtained basedon literature data which we could verify experimentally (15samples involving arc melting, annealing, water quenching, X-ray diffraction (XRD), and differential thermal analysis (DTA)).Applying this description of the Ni-Si system, as well as thedescriptions of the Ni-C and Si-C systems available from theliterature, preliminary calculations for the C-Ni-Si phaseequilibria were made in order to provide guidance in selectingthe compositions of decisive ternary alloys. These alloys weresubjected to an experimental procedure similar to that employedfor the Ni-Si alloys. The XRD and DTA measurements resultingfrom these ternary alloys provided accurate information on theinvariant reaction temperatures in the C-Ni-Si system.Comprehensive comparisons between calculated and measuredphase diagrams show that most of the experimental informationis satisfactorily accounted for by the present description of theC-Ni-Si system. The liquidus projection and reaction scheme forthe whole ternary system are presented.