Problem Solving Forum
May 29 - June 4, 2016
Is there a definitive relationship between mechanical properties of coatings (such as elongation and tensile strength) and crack-bridging capability?
Zenith Czora of Durotech Industries, Inc. on
June 2, 2016:
Tensile strength is measured as force, where as el ...read more Tensile strength is measured as force, where as elongation is measured as percentage. The difference is tensile strength is measuring the force that the sample membrane can withstand before it breaks, whereas elongation is measuring how far the sample can stretch. The greater the tensile strength, the more the resistance the membrane has to splitting. The elongation of a membrane may contribute to its ability to accommodate movement in the substrate or structure without rupturing.The crack-bridging capacity of a coating is determined by mechanical strength such as elongation, tensile strength, modulus of elasticity and toughness of the film. High tensile strength indicates the toughness of the coating. Elongation provides a good insight about the material behaviour while crack bridging testing may provides the real-life information of the coatings' ability to span cracks. It is directly proportional to film thickness. Temperature greatly affects the ability of a coating to elongate, that is, elongation values will be greatly reduced at colder temperatures.