The Vickers microhardness was measured on the coating sections using a Duramin hardness tester manufactured by Struers and a load of 300g. 10 indents were made, and the hardness value expressed as a mean value with standard deviation. (W 290) (1)

Mean value = Valor médio

The threshold value of 20 dB has been chosen as it represents an ultrasonically acceptable difference between an echo of significance and those which are considered to be spurious. (W 86) (2)

Threshold value = Valor limite

The actual results from Baldy do not report a threshold stress; instead, the occurrence of failure was recorded for different values of applied stress (typically four samples were tested at the same stress value). (W 208) (3)

Stress value = Valor de tensão

(1) Influence of spraying parameters on the properties of HVOF alumina coatings

M A Riley and A J Sturgeon, Cambridge, UK

Paper presented at International Thermal Spray Conference 2-4 May 2005, Basel, Switzerland.

(2) Coping with failed elements on an array: a modelling approach to the technical justification

Channa Nageswaran 

TWI Ltd Cambridge, UK

Paper from Insight vol.52, no.7, July 2010. pp.372 – 379.

(3) A review of the effect of cold-work on resistance to sulphide stress cracking

T Sourmail, TWI

Paper presented at Corrosion 2007, Paper 07104, March 11-15 2007 Nashville, Tennessee, USA.