Hard metals mission to Japan

1991 ◽  
Vol 46 (3) ◽  
pp. 6
Keyword(s):  
Hard Metals

scholarly journals Crystallographic and structural characterization of heterometallic platinum complexes Part VI. Heterohexanuclear complexes

2014 ◽  
Vol 12 (11) ◽  
pp. 1101-1126 ◽  
Author(s):  
Milan Melník ◽  
Peter Mikuš ◽  
Clive Holloway
Keyword(s):  
Metal Ion ◽  
Structural Parameters ◽  
Bond Distance ◽  
Transition Element ◽  
Platinum Complexes ◽  
Hard Metals ◽  
Wide Range ◽  
Platinum Clusters ◽  
Soft Metal ◽  
Independent Molecules

AbstractThis review classifies and analyzes heterohexanuclear platinum clusters into seven types of metal combinations:Pt5M, Pt4M2, Pt3M3, Pt2M4, PtM5, Pt2M3M′, and Pt2M2M2′. The crystals of these clusters generally belong to six crystal classes: monoclinic, triclinic, orthorhombic, tetragonal, trigonal and cubic. Among the wide range of stereochemistry adopted by these clusters, octahedral and capped square-pyramidal are the most common. Although platinum is classified as a soft metal atom, it bonds to a variety of soft, borderline and hard metals. Nineteen different heterometal ions are involved in hexanuclear platinum clusters. The shortest Pt-M bond distance in the case of M being a non-transition element is 2.395(4) Å for germanium and for M being a transition metal ion it is 2.402(2) Å for Cobalt. The shortest Pt-Pt bond distance observed in these clusters is 2.532 Å. Several relationships between the structural parameters are identified and discussed. Some clusters exist in two isomeric forms and some show crystallographically independent molecules within the same crystal. Such isomers and independent molecules are examples of distortion isomerism.

Interrelationship between the structure and properties of hard metals based on titanium carbide

1979 ◽  
Vol 18 (10) ◽  
pp. 739-744
Author(s):  
A. N. Pilyankevich ◽  
T. A. Shapoval ◽  
G. T. Dzodziev ◽  
V. N. Paderno
Keyword(s):  
Titanium Carbide ◽  
Structure And Properties ◽  
Hard Metals

Fundamental Property of Metals – Grain Boundaries Phase Transition as a Basis of Nanostructured Layers, Materials and Composites Production

2010 ◽  
Vol 654-656 ◽  
pp. 1852-1855 ◽  
Author(s):  
Y.A. Minaev
Keyword(s):  
Phase Transition ◽  
Grain Boundaries ◽  
Fundamental Property ◽  
Hard Metal ◽  
Surface Layers ◽  
Crystalline Materials ◽  
First Order Phase Transition ◽  
Hard Metals ◽  
Nanostructured Layers ◽  
First Order Phase

The obtained generalized equation for description of a fundamental property of solid crystalline materials i.e. first-order phase transition of the grain boundaries with formation of two-dimensional liquid has been used for calculating of transition temperature of any metals, which value lies in range 0.55 – 086 of melting point. Based on these conclusions to develop strategies for effective forming of coatings by synthesis of nitrides and carbonitrides on surface layers of hard metals and chromium steels have been made. It was shown the hardening of thin surface layer (0.1-0.5mm) due enriched of a nitrides in steels and carbonitrides with diamond like structure and strengthening the following layer by recristallization of W carbides in WC-Co and WC-TiC-Co hard metal. These result to increase of alloys hardness, ductility, and resistance to wear and decrease of sensibility to fragile rupture. Industrial tests have been made.

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