The trend towards miniaturized components, combined with the functionalization of thin coatings, has generated a need for suitably sophisticated methods for characterization of mechanical load-bearing capacity. Nanoindentation allows local determination of hardness and Young’s modulus for ultra-thin coatings (> 300 nm), with resolution in the micron range. At Chemnitz University of Technology (TU Chemnitz), the Institute of Materials Science and Technology is using an Asmec nanamomechanical tester for current research projects.
A key area of research for the Professorship of Surface Technology and Functional Materials at TU Chemnitz concerns the mechanical properties of thin and thick coatings. This includes determination of hardness in the macro and micro ranges and, most importantly, investigations in the nano hardness range. By determining hardness in different phases of a coating or a composite, together with the hardness of carbides in coatings and substrates and hardness gradients of substrates/coatings, the aim is to determine (among other things) the maximum load-bearing capacity of thin coatings.
For determination of the above characteristic values TU Chemnitz uses an Asmec nanomechanical tester. This test combines two measuring heads, in the normal direction (nanoindenter principle) and in the lateral direction (scratch-tester principle). The heads operate completely independently of each other and feature namometer resolution. This approach enables measurement of lateral force-displacement curves, from which various material parameters can be obtained. This includes measurement of lateral stiffness and the purely elastic lateral deformation of the specimen.
“A system which can be recommended for a wide variety of practical and research-related applications from a maximum force of around 0.3 mN and above, depending on the material,” is how Professor Dr.-Ing. habil. Thomas Lampke, Head of Surface Technology and Functional Materials, describes the tester’s role in the TU’s testing laboratory.
Images: TU Chemnitz