Plasma, HVOF and other Engineering Coatings

There are two ways of conducting tensile pull-off testing of thermal sprayed coatings:

  1. Testing directly on the coated components or coated test panels;
  2. Pulling apart two test cylinders which are glued together where one of them have been coated (ASTM-C633).

It is recommended to use the automatic adhesion testing machines for these types of coatings due to test speed constraints in the testing standards and the fact that it is easier to to carry out the these high-force tests consistently with an automated process.

1) Testing on test panels/directly on component

The following models are available for testing of engineering coatings:

An automatic adhesion testing machine particularly for use with small test elements. Certified testing range of up to 102 MPa/14800 psi. with Ø8.16mm test element.

A more powerful automatic adhesion testing machine particularly for use with larger (Ø25mm/one inch) test elements. Certified testing range of up to 68 MPa/9800 psi.

The most powerful model when a combination of high strength coating and large test elements (Ø25mm/one inch) are required. Certified testing range of up to 136 MPa/19700 psi.

2) ASTM-C633 Tensile Testing of Coatings

Two cylinders with Ø25mm/one inch diameter, one of which is coated with the sample coating, are glued together end-to-end and then pulled apart in order to measure the pull stress (measured in Newton/mm2 or psi) required to fracture the coating.

The ASTM-C633 tensile testing jig is used with the PAT range of pull-off testers to perform pull testing in accordance with ASTM-C633.

Users of the PAT equipment for testing of thermal sprayed coatings say that the test results with the PAT equipment are equal, if not better than those achieved with with traditional tensile testing equipment, which are both more complicated and expensive than the portable PAT unit.

ASTM-C633 Jig
Ancillary equipment to enable pull testing of two cylinders glued together end-to-end in a consistent and reproducible way.

All the above models are compatible with the testing jig

The full benefit of the Dynamic Force Distribution is used even in the ASTM jig. This ensures as high test repeatability as the coating will allow.