Hi ... new here.
I work for a company that designs and builds test apparatus and machinery for industrial companies. I am currently working on a machine to test wear resistance and frictions of heavy-duty industrial greases. The first prototype is a block on an oscillating cylinder with controlled normal force. It works more or less but we found out that there were way more questions generated by the first results than useful data.
One question that keeps bugging me is how to manage the grease application. The purpose of the test to sort out various greases according to their relative wear resistance. I’ve probably read a hundred papers on best practices, etc, but none that answered this fundamental question:
Should grease be applied and the test run, without replacing the grease as it’s squeezed out? ... i.e. treat the grease as if one test parameter was how long the grease managed to maintain a film thickness before being squeezed to the point that contact occurs.
Should the grease be injected under pressure throughout the test to make sure the apparatus doesn’t run out of grease?
I think we want to avoid three-body wear scenarios. If the test creates abrasive wear particles large as the film thickness then I think we’re testing abrasive wear of the two materials but not the grease, itself.