The Inverse Problem Of Martensitic Transformation In CuAlNi Alloys

With the deepening of the research of martensitic transformation in recent years, the martensitic transformation is widely applied in the field of industrial production and other related. Martensitic transformation in the process of showing the unique shape memory effect of essence is based on the reversibility of martensite transformation. However, the existing theory of martensite transformation mechanism is not on the dynamic process of explanation, so there are still many unknown fields, this is largely limits the martensite phase transformation further application in practical engineering.Cu Al Ni alloy in copper base shape memory alloy has a good application potential, phase change before and after the lattice structure is relatively simple, and it has a strong elastic anisotropy. Martensite transformation process with the release of elastic wave, acoustic emission. It is directly related to the phase transition constitutive, therefore, the acoustic emission can be used to study the phase transition constitutive and mechanism. In this paper, from the point of view of the inverse problem of acoustic emission research phase transition constitutive Cu Al Ni alloy.First of all, The paper makes a mechanism of martensite phase transformation model for the reasonable inference, limit the two-dimensional problem. And put forward a simplified three-step parameterized phase transition constitutive. Based on sound wave propagation equation code compiled the two-dimensional acoustic field evolution, and by using the calculation for the sample on the surface of the acoustic emission signal. Paper also studied the influence of the phase transition constitutive parameters on the acoustic field, formed the sample library. Acoustic emission is presented to solve the inverse problem is based on the sample surface test signal characteristics and comparison, the phase transition constitutive parameters were obtained.Results show that the acoustic emission of the inverse problem to study the mechanism of martensite phase transformation is feasible, can be judged by assuming that the rationality of the phase transition constitutive model, and can get the parameters in the model inversion. Can also be constantly revised parameterized constitutive model, make it more close to the physical mechanism.