Arc-sprayed coatings normally have adhesion strengths exceeding those of flame sprayed coatings.
Two main factors determine which strength adhesion tester must be used:
- The adhesion strength of the coating
- The required size of test elements
If the maximum strength of a coating is 45 MPa and the test element size is Ø25mm the total pull force required is 22 kN, i.e. the 40kN testing head must be used. If there are no restriction on the test element the size Ø8.16mm can be used with a total required pull force of 2.4 kN, i.e. the 6.3 kN testing head can be used.
Five models can normally be used for adhesion testing of arc sprayed coatings:
GM01/6.3kN – A manual adhesion tester which is very practical if small test elements can be used. Max. testing range of up to 120 MPa/17400 psi. with Ø8.16mm test element.
GM04/40kN – A manual adhesion testing unit required if Ø25mm/one inch test elements are specified. Max. testing range of up to 80 MPa/11600 psi. with Ø25mm/one inch test element.
AT101E/6.3kN – 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.
AT101E/40kN – 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.
AT101E/80kN – The most powerful automatic model when a combination of high strength coating and large test elements ( Ø25mm/one inch) are required.