Ceramic-Based Speckles and Enhanced Feature-Detecting Algorithm for Deformation Measurement at High Temperature

The mechanical properties of Ni-base alloys have drawn considerable attention owing to their wide application in the hot components of aircrafts and gas turbines. To accurately measure the deformation of Ni-based alloys at high temperatures, a new type of high-temperature speckles is fabricated on the surface of specimens subjected to long heating durations at temperatures up to 1400 °C. Meanwhile, a novel measurement method based on the scale-invariant feature transform algorithm is developed to measure the deformation and obtain a more accurate result. Both of the above proposed methods are used in a creep test of Inconel 713C at 860 °C. The experimental results indicate that the speckles exhibit excellent performance under heating conditions and adhere well to the substrate at high temperatures. Also, the proposed deformation measurement method exhibits superior image processing even when the speckle quality is imperfect with respect to speckle size.