The crystallography and morphology of Mo2C in ferrite

The orientation relationships between hexagonal Mo2C precipitates (H) in ferrite (B) have been determined by electron diffraction to an accuracy of +/-2degrees. With one exception, the 19 results are consistent with the previously reported Pitsch and Schrader (P/S) orientation relationship. However, these more accurate determinations show clearly that there is a systematic deviation of up to 5.5degrees from the exact P/S relationship and that this deviation consists of a small rotation about the parallel close packed directions-[100](B)//[2 (1) over bar(1) over bar0](H). The long direction of the Mo2C needles has been determined unequivocally in terms of the orientation relationship to be [100](B)//[2 (1) over bar(1) over bar0](H). Moire fringes between precipitate and matrix have been used to improve the accuracy of the orientation relationship results and to determine the lattice parameters of the carbide precipitates investigated. The Moire fringe analysis has shown small systematic departures from the exact parallelism between [100](B) and [2 (1) over bar(1) over bar0](H) along the length of Mo2C needles and a lowering of the carbide lattice parameter that is consistent with the replacement of Mo by Fe in the carbide. The orientation relationship results, including the observed systematic deviation from the exact P/S relationship, are shown to be consistent with the edge-to-edge model. (C) 2002 Kluwer Academic Publishers.

Accurate orientation relationship between ferrite and austenite in low carbon martensite and granular bainite

Convergent beam Kikuchi diffraction was used to accurately determine the orientation relationships (ORs) between austenite and martensite, and between austenite and granular bainite in two Fe-Ni-Mn-C alloys. Both martensite and granular bainite have the same crystallographic characteristics with the OR: (111)(A)parallel to(101)(F), [1 (1) over bar0](A) 2.5degrees +/- 2degrees from [1 (1) over bar(1) over bar](B).

Liquidus temperatures in calcium ferrite slags in equilibrium with molten copper

Experimental laboratory methods have been developed that enable phase-equilibria studies to be carried out on slags in the system Ca-Cu-Fe-O in equilibrium with metallic copper. These techniques involve equilibration at temperature, rapid quenching, and chemical analysis of the phases using electron-probe X-ray microanalysis (EPNIA). Equilibration experiments have been carried out in the temperature range of 1150 degreesC to 1250 degreesC (1423 to 1523 K) and in the composition range of 4 to 80 wt pct "Cu2O," 0 to 25 wt pct CaO, and 20 to 75 wt pct "Fe2O3" in equilibrium with metallic copper. Liquidus and solidus data are reported for the primary-phase fields of spinel (magnetite) and dicalcium ferrite. The resulting data have been used to construct liquidus isotherms of the CaO-"Cu2O"-"Fe2O3" system at metallic copper saturation.

Synthesis and characterization of Pd(II) and Pt(II) complexes with triazolopyrimidine derivatives: The crystal structure of [Pd2L2Cl4] where L=5,7-dimethyl-1,2,4-triazolo[1,5-a]pyrimidine

The Pd(II) and Pt(II) complexes with triazolopyrimidine C-nucleosides L-1 (5,7-dimethyl-3-(2',3',5'-tri-O-benzoyl-beta-D-ribofuranosyl-s-triazolo)[4,3-a]pyrimidine), L-2 (5,7-dimethyl-3-beta-D-ribofuranosyl-s-triazolo [4,3-a]pyrimidine) and L-3 (5,7-dimethyl[1,5-a]-s-triazolopyrimidine), [Pd(en)(L-1)](NO3)(2), (Pd(bpy)(L-1)](NO3)(2), cis-Pd(L-3)(2)Cl-2, [Pd-2(L-3)(2)Cl-4]center dot H2O, cis-Pd(L-2)(2)Cl-2 and [Pt-3(L-1)(2)Cl-6] were synthesized and characterized by elemental analysis and NMR spectroscopy. The structure of the [Pd-2(L-3)(2)Cl-4]center dot H2O complex was established by Xray crystallography. The two L-3 ligands are found in a head to tail orientation, with a (PdPd)-Pd-... distance of 3.1254(17) angstrom.L-1 coordinates to Pd(II) through N8 and N1 forming polymeric structures. L-2 coordinates to Pd(II) through N8 in acidic solutions (0.1 M HCl) forming complexes of cis-geometry. The Pd(II) coordination to L-2 does not affect the sugar conformation probably due to the high stability of the C-C glycoside bond. (c) 2006 Elsevier B.V. All rights reserved.