National Aeronautics and Space Administration


Date of this Version



Materials Science and Engineering A 527 (2010) 2129–2135; doi:10.1016/j.msea.2009.11.064


Metallic Cu–8%Cr, Cu–26%Cr, Cu–8%Cr–1%Al, NiAl and NiCrAlY monolithic coatings were fabricated by

vacuum plasma spray deposition processes for thermal expansion property measurements between 293

and 1223 K. The corrected thermal expansion, (∆L/L0)thermal, varies with the absolute temperature, T, as

( ∆L ) = A(T-293)3 + B(T-293)2 + C(T -293) + D


where A, B, C and D are regression constants. Excellent reproducibility was observed for all of the

coatings except for data obtained on the Cu–8%Cr and Cu–26%Cr coatings in the first heat-up cycle, which

deviated from those determined in the subsequent cycles. This deviation is attributed to the presence of

residual stresses developed during the spraying of the coatings, which are relieved after the first heat-up

cycle. In the cases of Cu–8%Cr and NiAl, the thermal expansion data were observed to be reproducible

for three specimens. The linear expansion data for Cu–8%Cr and Cu–26%Cr agree extremely well with

rule of mixture (ROM) predictions. Comparison of the data for the Cu–8%Cr coating with literature data

for Cr and Cu revealed that the thermal expansion behavior of this alloy is determined by the Cu-rich

matrix. The data for NiAl and NiCrAlY are in excellent agreement with published results irrespective of

composition and the methods used for processing the materials. The implications of these results on

coating GRCop-84 copper alloy combustor liners for reusable launch vehicles are discussed