THE MOLYBDENUM—ZIRCONIUM—CARBON SYSTEM¹

Processing of ZrC–Mo Cermets for High‐Temperature Applications, Part I: Chemical Interactions in the ZrC–Mo System

“…The Mo 2 C peaks exhibited decreasing intensity with increasing temperature until they were undetectable at 2100°C. This is consistent with phase equilibria studies on the Zr–C–Mo system 11,12 . The isothermal sections from these studies are shown in Fig.…”

“…Lattice parameters of the ZrC phase (ICDD #73‐0477) were calculated by Rietveld refinement performed using Riqas Software (Materials Data Inc., Livermore, CA). The calculated lattice parameters were then compared with literature values 11 to calculate the amount of Mo in solid solution with ZrC. The amount of Mo 2 C (ICDD #79‐0744) was determined by comparing the relative area of the Mo 2 C (121)(102) peaks with the Al 2 O 3 (104) peak from the internal standard (ICDD #88‐0826), which was, in turn, correlated to a set of Al 2 O 3 –Mo 2 C powder mixtures with Al 2 O 3 added in 10 wt% increments from 0 to 100 wt%.…”

“…In the studies on ZrC and Mo cermets, specimens were produced by arc melting at 3000°C in an Ar atmosphere with subsequent annealing of the cast material 8–10 . Arc melting was also used in previous phase equilibria studies on this system 11–13 …”

Carbides

“…The Zr-Mo-G system, studied 138 for the 2,100°C section, is interesting and consistent with our systematic considerations in that it shows a large ZrC->Mo 3 C 2 solution region, extending right up to Zro.02M02.9G2, i.e. only the last abandonment of Zr causes a structure switch.…”

Ternary Phase Equilibria in Transition Metal-Boron-Carbon-Silicon Systems. Part 1. Related Binary Systems. Volume 1. Mo-C System

“…006 Z, and c = 14.61X(7) (7)) The structure of 11-MoG is closely related to the cubic Bl-type ( ) . The phase is stable only at high temperatures ( 7 ) decomposing into Mo C and graphite at 1450 + 1000 (13 (Table 3).…”