Ti-Al intermetallic compound alloy transition liquid phase diffusion weld composite connection method

Abstract

Disclosed is a Ti-Al intermetallic compound alloy transition liquid phase diffusion welding composite connection method, by welding the Ti3Al alloy with the method, the room temperature strength and the high-temperature strength of the joint can reach over 80% of the mother metal's strength, equal plasticity with the mother metal can be obtained under room temperature, the joint can achieve uniform structure similar to the mother metal.

Description

technical field [0001] The invention relates to a material connection method, in particular to a Ti-Al intermetallic compound alloy transition liquid phase diffusion welding composite connection method. Background technique [0002] Ti 3 Al intermetallic compound is a new type of metal-based superalloy, compared with ordinary titanium alloy, its density (3.8 ~ 4.2g / cm 3 ) is equivalent, and the use temperature is higher. The working temperature of ordinary titanium alloys is still limited to below 600 °C so far, Ti 3 The working temperature of Al intermetallic compound is 600-750 ℃, or even higher, and it also has the advantages of high-temperature specific strength, high specific modulus, high-temperature oxidation resistance and high-temperature creep, and can reduce weight by 40% compared with nickel-based superalloys. about. Therefore, it has developed rapidly in recent years, and has entered into engineering applications, and is widely used in the manufacture of str...

AI Technical Summary

Problems solved by technology

[0008] The main problem of fusion welding is: the weld seam and the heat-affected zone (especially the area near the fusion line) are prone to brittle structures and even cracks. At the same time, non-vacuum fusion welding processes inevitably introduce interstitial elements (such as oxygen , nitrogen and hydrogen, etc.), this element generally has deleterious effects

[0014] All research data show that: so far Ti 3 The brazing and diffusion welding technology of Al-based alloys still has the following deficiencies: (1) The existing researches are all aimed at Ti with lower Nb content. 3 Al-based alloys are carried out, for high Nb content Ti with higher mechanical properties 3 There is a lack of research on Al-based alloys and dual-phase alloys dominated by O phase; (2) The room temperature strength of the joint is 548MPa, the high temperature strength is 485MPa (650°C), and the plasticity is lower than that of the base metal