SMEAR / PULL OUT

[Justin]

Dear all

Is anyone able to describe how to identify SMEAR / PULL OUT when evaluating a mount?

It is nice to explain both via micrographs.

Thanks.

Justin

[Gordon]

Hi Justin

It is extremely difficult to identify SMEAR / PULL OUT when evaluating thermal spray coatings.

A very useful tool is to impregnate the coatings with epoxy resin prior to mounting. This tends to stop smearing over of the epoxy filled porosity sites and with the more friable coatings adds strength and reduces pull-out.