Choice of metal materials for responsible parts and vehicle assemblies operating under the conditions of low temperatures

Abstract

Abstract The purpose of the present study is to evaluate the cold resistance and develop an algorithm for selecting metals that are widely used for manufacturing critical parts and components of vehicles operating in a wide range of low temperatures. To achieve this goal, the tests were made on impact bending of the studied metals in the temperature range of climatic cold, followed by the study of fractures of metal samples. The studies were carried out using methods of optical and electron microscopy and fracto-graphic studies. During the study, data were obtained on the change in toughness, the mechanisms of metal destruction for a wide range of low temperatures, as well as the temperature of the viscous-brittle transition of the studied metals. It has been found that materials with an FCC and HCP lattice exhibit greater resistance to fracture at low temperatures. It is shown that a change in the fracture mechanism is closely related to their crystal structure features and thermal conductivity. As a result of the research, an algorithm for the selection of cold-resistant materials was developed, and on its basis- a program.