A method for preparing high-nb titanium-aluminum-based alloy anti-oxidation coating on the surface of titanium alloy

Abstract

The invention discloses a method for preparing a preparing high-Nb titanium aluminum based anti-oxidization coating on a titanium alloy surface. According to the method, by utilizing in-situ synthetic reaction and thermal treatment of Ti-Al-Nb blended element powder under action of a CO2 laser beam, a high-Nb titanium aluminum coating layer is prepared on the titanium alloy surface. The method comprises the following preparation steps: titanium alloy surface pre-treatment, powder preparation and ball-milling, powder presetting, powder laser sintering, coating thermal treatment, anti-oxidization performance test and microscopic structure analysis. According to the performance test results, the method can effectively reduce vigorous oxidation, in a high-temperature environment, of the titanium alloy, and greatly improves usage temperature limit of the titanium alloy. The invention provides the coating preparation method which is short in period, low in comprehensive cost and high in flexibility degree. On the premise of not greatly affecting the high temperature anti-oxidization performance of the alloy coating, a coating component proportion is flexibly regulated to obtain a high-Nb titanium aluminum based alloy dual-phase coating which is high in compactness, uniform in thickness and excellent in anti-oxidization performance.

Description

technical field [0001] The invention relates to a method for preparing a high-Nb titanium-aluminum-based alloy anti-oxidation coating on the surface of a titanium alloy, and belongs to the technical field of surface modification of laser cladding materials. Background technique [0002] Due to its specific strength, high specific modulus, good biocompatibility and excellent acid and alkali corrosion resistance, titanium alloys are widely used in aerospace, medical and health, marine development, energy, chemical and machinery manufacturing and other fields. At present, it is a light-weight and high-strength structural material with excellent comprehensive performance. However, the high-temperature oxidation resistance is insufficient, especially when the violent oxidation occurs above 600 ° C and fails, the service temperature of most titanium alloys is limited to about 600 ° C. At present, the limit service temperature of titanium alloys developed by traditional titanium a...

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Problems solved by technology

[0005] However, the production of special high-Nb titanium-aluminum-based alloy laser cladding powder by smelting an alloy with an appropriate composition has the following problems: During the smelting process, the burning loss of alloy elements makes the alloy composition fluctuate greatly, and impurity elements are inevitably mixed into the alloy solution; After solidification of the liquid alloy, the macro / micro segregation causes the alloy composition to have obvious fluctuations in space, and the coating consistency is low; Some alloying elements are highly active at high temperatures, and their melting conditions are very demanding; The composition of the coating is difficult to adjust, and the preparation cost of special alloy powder is high

The above research on high-temperature oxidation-resistant coatings mainly focuses on preparing coatings on the surface of titanium alloys to improve their high-temperature oxidation resistance by impregnation, magnetron sputtering, vapor deposition, and plasma spraying. There are still relatively few studies on the preparation of high-temperature oxidation-resistant coatings on the surface of titanium alloys by synthesis technology and post-treatment to improve their high-temperature oxidation resistance.

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