Predicting the mechanical properties and composition optimization of a burn-resistant titanium alloy for aero-engines

Abstract

Lightweight high-temperature titanium alloys are a key material for aero-engines. With the increasing use of new titanium alloys in aero-engines, titanium fire has become a typical catastrophic fault that plagues material design and selection. A burn-resistant titanium alloy is a special material developed to deal with the problem of titanium fire. Its application in aero-engines has become one of the key technologies for the prevention and control of titanium fire. Therefore, explaining the influence of the alloying elements of burn-resistant titanium alloys on mechanical properties is important to provide an important theoretical basis for the design and application of these alloys. Based on the experimental data, the relationship model between the alloying elements and mechanical properties of a burn-resistant titanium alloy was established using a support vector machine algorithm, and the effect of the alloying elements on the mechanical properties was analyzed. The input parameters of the model were V, Al, Si, and C elements, and the output parameters were the room temperature tensile properties (tensile strength, yield strength, elongation, and the reduction of area). Results show that the linear correlation coefficient of each mechanical property of the SVM model is above 0.975, which signifies good prediction ability. The absolute percentage error between the predicted and experimental values of each mechanical property test sample is within 5%, indicating good generalization ability and an effective reflection of the quantitative relationship between the alloying elements and mechanical properties of the burn-resistant titanium alloy for optimizing the composition of the alloy. The mechanical properties of the Ti–35V–15Cr alloy can be improved by adding 0–0.1% Si element and 0.05%–0.125% C element and reducing 2%–5% V element. Meanwhile, the mechanical properties of the Ti–25V–15Cr alloy can be improved by adding 1.5%–1.8% Al element and 0.15%–0.2% C element.

Keywords

• burn-resistant titanium alloy
• support vector machine algorithm
• alloying elements
• mechanical properties
• composition optimization