Order hardening of Pt8X alloys

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Vol. 445-446; pp. 336 - 340
• Main Authors: NXUMALO, S, NZULA, M. P, LANG, C. I
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier 01-02-2007
• Subjects: Condensed matter: structure, mechanical and thermal properties; Constant-composition solid-solid phase transformations: polymorphic, massive, and order-disorder; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Materials science; Mechanical and acoustical properties of condensed matter; Mechanical properties of solids; Phase diagrams and microstructures developed by solidification and solid-solid phase transformations; Physics; Tribology and hardness; Vanadium alloys; Electron diffraction; Platinum alloys; Metallography; Chromium alloys; Hardness; Heat treatments; Binary alloys; Hardening; Heat of transformation; Dark field microscopy; Superstructure; Ordering
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2006.09.048

Platinum containing around 11.1at.% chromium or vanadium undergoes an ordering transformation upon heat treatment, resulting in the formation of ordered domains with the Pt8Ti superlattice structure. The formation of these ordered domains, which are dispersed in a disordered matrix, results in an increase in hardness. Hardness is observed to be sensitive to domain size, with a maximum hardness at around 5nm, if the ordered volume fraction is high.