Open Access
Article
15 September 2025Heat Resistance of Centrifugally Cast Tubes Made of 32%Cr-43%Ni Refractory Alloy and Its Welded Joints at Temperatures up to 1150 °C
The results of microstructura l analysis, short-term and long-term strength tests of modified sparingly alloyed refractory alloy of 32%Cr-43%Ni and its welded joints are presented. A quantitative analysis of the dispersed phases in the initial state and after long-term strength tests has been carried out. It is shown that the network of carbide-intermetallic precipitates persists after long-term strength tests at a temperature of 1150 °C. This ensures the ability of the developed alloy and its welded joints to withstand high-temperature creep for a long time. It has been established that after long-term strength tests at a temperature of 1150 °C, niobium carbide particles present in the base metal and weld metal are almost completely transformed into an intermetallic phase based on Cr-Ni-Si-Nb-N. The penetration of atmospheric nitrogen into the metal stimulates this process.
Open Access
Review
29 September 2025Review of Gallium Nitride Devices and Integrated Circuits at High Temperatures
In various industrial applications, including aviation, electric vehicles, and drilling, the demand for semiconductor devices and associated circuits with high thermal stability is progressively increasing. Wide-bandgap semiconductor Gallium Nitride (GaN) devices exhibit the advantages of fast switching capability, low on-resistance, and the ability to operate at high temperatures. These advantages have made them potential candidates for integrated circuits in high-temperature environments in recent years. Lateral GaN devices promote monolithic integration, which consequently increases power density and reduces cost of cooling systems. Hence, it is worthwhile to investigate the performance of GaN devices in high-temperature environments. This review aims to present a thorough review of high-temperature characteristics of GaN devices and integrated circuits. The performance of GaN devices at high temperatures, such as threshold voltage，saturation current and on-resistance, has been reviewed in response to different structures. The underlying degradation mechanisms related to the intrinsic properties of structures and fabrication technology are discussed at high temperatures. The thermal performance of GaN small signal integrated circuits and power converters was presented. This paper systematically examines the advantages and challenges of GaN devices and integrated circuits at high temperature environments.