Standardized test and measurement methods based on the VDI 2248 guideline

Shape memory alloys (SMA) have many advantages, such as their low weight and noiseless operation. Nevertheless, only a few products exist on the market. One reason for this lies in the complex properties of this alloy, which product developers often have problems with. In particular, standardization is therefore an essential factor for better dissemination of this technology. The series of guidelines of the Association of German Engineers (VDI) 2248 "Product Development with SMA" therefore supports the user in the functional design of technical solutions with shape memory alloys and even defines a uniform terminology. In order to provide users with a structured explanation of this technology, the guideline is subdivided into six different guideline parts (sheets).

Sheet 3 "Test and Measurement Methods", presented in this paper, describes methods for determining the mechanical, physical and, in particular, functional characteristics of SMA. With regard to the mechanical characteristics, the tensile test is presented as the most important measuring method and the special features of the testing of SMAs are pointed out. To determine the transformation temperatures, calorimetric or bending test methods are explained. Special test methods have been developed for the functional examination, which are also described in sheet 3. A table provides further assistance in selecting the measuring methods. In particular, the areas of quality assurance and materials testing will find valuable information in this guideline sheet. In addition, a certification is in the planning, which is to ensure the guideline-compliant testing of SMAs.