Overview of EP15ND-2
Master Bond EP15ND-2 is a single component, heat curing epoxy specifically designed for testing the strength of thermal sprayed coatings as indicated by ASTM C633. Featuring exceptionally high tensile strength exceeding 12,000 psi, as well as unlimited working life at room temperature, the formulation is 100% reactive, forming dimensionally stable bonds with minimal shrinkage upon cure. In this study, EP15ND-2 was utilized per the ASTM C633 test to analyze the tensile strength of a wide variety of thermal sprayed coatings.
Application
Scratch testing is frequently used to determine the strength properties of thin coatings, but for thick, thermal sprayed coatings, the accepted protocol to determine the strength is ASTM C633. However, the authors of this study attempt to develop an appropriate scratch test for thermal sprayed coatings, as scratch testing is simpler and would “reduce testing time and cost”1 compared to the conventional ASTM protocol. By testing a variety of thermal sprayed coatings using both methodologies, the authors aim to determine the validity of the scratch test by correlating the results of the two techniques, as well as exploring any trends discovered. Since the ASTM C633 protocol requires a high tensile strength adhesive to prepare samples for testing, the authors used EP15ND-2 for this purpose.
Key Parameters and Requirements
The study investigated a variety of materials, selected to represent frequently used commercially available thermal sprayed coatings. All coatings were thermally applied, using spraying techniques appropriate for the material type, to a stainless-steel substrate with a high surface roughness to ensure bonding. After spray coating, each specimen type was further prepared in two different ways as the scratch and ASTM tests have different requirements. For the scratch test, the specimens were mounted in an epoxy resin, whereas for the ASTM C633 test, the specimens were prepared per the protocol, using EP15ND-2 as the adhesive.
To find out more about the coating types and spray techniques, and to learn the results, please download the full case study here.
Download full case studyReference
1 Koipraset, H., Thaiwatthana, S., Sheppard, P. (2015, Jan 12-16). Scratch Testing for Evaluating Cohesive Bond Strength of Thermal Sprayed Coating. The International Symposium on Fusion Science and Technology. Phra Nakhon Si Ayutthaya, Thailand.