With the development of engineering technology, more and more materials have been applied. Among them, niobium and its alloys have become an important part of high-temperature structural materials due to their excellent properties such as high-temperature strength, corrosion resistance, and oxidation resistance. This type of alloy is widely used in aerospace, nuclear engineering, high-speed railway and other fields. This article aims to explore the performance of low-density niobium alloys and niobium-hafnium alloys during electron beam welding.
Part One Research Current Situation
Niobium and its alloy materials are widely used due to their special physical and chemical properties, outstanding corrosion resistance, high temperature strength and good mechanical properties in high temperature environments. At present, the processing technology of niobium and its alloy materials has become more and more mature, and electron beam welding is one of the commonly used methods. Electron beam welding has the advantages of smaller welding seams, fast welding speed, high power density, small heat input, and small thermal impact on welding materials. Therefore, it is widely used in high-end manufacturing fields and aerospace and other fields. Since niobium alloys are widely used, their performance in electron beam welding is also worth exploring.
Part 2 Performance Analysis of Low Density Niobium Alloys and Niobium-Hafnium Alloys
Low density niobium alloy
Low-density niobium alloy, because its density is about 10% lower than that of pure niobium, contains a small amount of inclusions such as metal element V, Cr, Ti, etc., thus forming a coarse cell structure with a spherical mica interior. Due to the dual-phase structure of low-density niobium alloy, its physical and chemical properties are different from those of single-phase structure. The thermodynamic properties, physical and chemical properties of crystals are one of the important factors affecting the thermal processing and performance of materials. Therefore, the crystal structure and thermodynamic properties of low-density niobium alloys have an important impact on the performance of niobium alloys.
Niobium-Hafnium Alloy
Niobium and hafnium alloys are a commonly used high-temperature structural material. The addition of hafnium can significantly improve the strength, ductility, oxidation resistance and other properties of niobium, becoming an excellent strengthening element for niobium. The crystal structure of niobium-hafnium alloy is different from other niobium alloys. The hafnium and niobium atoms in it form a “nano lattice” structure. This structure makes the niobium-hafnium alloy have good processing properties and high temperature stability, and its oxidation resistance at high temperatures is also very good.
Part 3 Electron Beam Welding Performance Analysis
Low-density niobium alloy and niobium-hafnium alloy are two very excellent niobium alloy materials. How do they perform in electron beam welding? In response to this problem, our team conducted relevant experiments and obtained preliminary experimental results.
Welding performance of low density niobium alloy
Low-density niobium alloy shows good welding performance in electron beam welding, the weld quality is high, and the inclusions in the alloy are well dispersed, which improves the quality of the welded joint. The strength of the welded joints still meets the standard requirements, and the welding process specifications such as the spot penetration depth, welding angle, and weld spacing of the joints meet the general requirements and perform well.
Welding properties of niobium-hafnium alloy
Electron beam welding of niobium-hafnium alloys has also shown good performance. Firstly, the strength of the alloy has not been significantly reduced; secondly, the quality of the welded joints meets the standard requirements. Post-weld heat treatment can significantly improve the strength and ductility of welded joints.
Part 4 Conclusion
Ultimately, we can draw the following conclusions:
Low-density niobium alloy and niobium-hafnium alloy materials both show excellent performance in electron beam welding;
The electron beam welding strength and ductility of low-density niobium alloys and niobium-hafnium alloys can be improved through heat treatment;
During the electron beam welding process, attention should be paid to technical details and the correct welding process should be mastered to ensure the quality of the welded joints.