INDENTATION AND PROFILOMETRY AS A SIMPLIFIEDMETHOD OF DETERMINING RELATIVE ADHESIONSTRENGTH OF THERMAL SPRAY COATINGS

摘要

Adhesion to a substrate is an important aspect of a coatings performance. Many tests exist tornmeasure coating adhesion strength that requires numerous steps for sample preparation. Usingrnprofilometry and indentation, the relative bond strength of a coating can be determined withoutrnthe need for extensive sample preparation. A profilometer can be used to trace a marked line onrnthe coating surface which can then be retraced after an indentation is made, to determinerninterfacial crack length between the coating and substrate. Samples of Kapton? Cirlex? andrncompression molded composites of PMR-15 and PMR-II-50 with carbon TS650-35 fabric werernplasma sprayed with zinc and then indented, while adhesion pull tests were conducted onrnsimilarly coated samples. Kapton? Cirlex? exhibited the shortest interfacial crack length of thernthree materials indicating that it had better bonding than the composites. Kapton? Cirlex? hadrnhigher adhesion pull strength than the composites. Results from indentation/profilometry and thernadhesion pull tests indicated that there was no significant difference in bond strength betweenrnPMR-15 and PMR-II-50/TS650-35 composites. There was good correlation betweenrnindentation/profilometry and adhesion pull test results. Indentation and profilometry are shownrnto be viable means of screening the relative bond strength of coatings without the need for usingrninvolved adhesion test methods.