Investigation of failure in paint films

Abstract

Direct “pull-off” tests have been carried out on mild steel plates coated with an “Alloprene”-based lacquer. Several unusual features were observed on the fracture surfaces, and attempts have been made to interpret these markings, and the implications of their origin on the test methods employed. Preliminary results led to an improved testing method but new markings were produced which have been interpreted, and appear to be caused by the interaction of periodic stress waves with the fracture. This technique has the advantages of reproducibility and simplicity.