Article ID Journal Published Year Pages File Type
1450414 Acta Materialia 2006 12 Pages PDF
Abstract

The tensile creep properties of a β-rich (Ni,Pt)Al diffusion coating have been determined at various strains over the temperature range 800–1000 °C by deconvoluting the creep response of layered composite specimens under constant stress conditions. It is found that the creep strength of the diffusion coating tends to be higher than that of a similar coating tested previously by Pan et al. [Pan D, Chen MW, Wright PK, Hemker KJ. Acta Mater 2003;51:2205]. Associated with the higher strength is a relatively high creep activation energy (∼600 kJ/mol) and a high stress dependence of creep rate which increases with creep strain from ∼6.8 at 1% strain to ∼9.4 at 9% strain. These high values and the associated high creep strength are attributed to the formation, at the creep temperatures, of a fine dispersion of second-phase particles, presumed to be γ′ and possibly α-Cr, within the β-(Ni,Pt)Al matrix. It is suggested that the extent of this transformation and, hence, the strengthening effect are related to the original aluminium and platinum content of the coating.

Related Topics
Physical Sciences and Engineering Materials Science Ceramics and Composites
Authors
, , , ,