The optimal composition for a titanium alloy with high strength, low density, and excellent corrosion resistance for aerospace applications is the Ti-6Al-4V alloy, also known as Grade 5 titanium. This alloy consists of 90% titanium, 6% aluminum, and 4% vanadium. Ti-6Al-4V is the most widely used titanium alloy in the aerospace industry due to its excellent combination of properties.Thermal treatment conditions for Ti-6Al-4V to achieve the desired properties are as follows:1. Solution treatment: The alloy is heated to a temperature between 1650F 900C and 1750F 950C and held at this temperature for a period of time usually 1-2 hours to allow the alpha and beta phases to homogenize. This process helps to improve the alloy's strength and ductility.2. Quenching: After solution treatment, the alloy is rapidly cooled to room temperature, typically by water or forced air. This rapid cooling helps to retain the beta phase, which contributes to the alloy's high strength.3. Aging: The quenched alloy is then heated to a temperature between 900F 480C and 1000F 540C and held at this temperature for a period of time usually 8-24 hours . This aging process allows the precipitation of alpha phase within the beta matrix, which further increases the alloy's strength.To achieve the best balance of properties, it is essential to carefully control the thermal treatment conditions, such as temperature, time, and cooling rates. The specific conditions may vary depending on the desired properties and the specific application of the titanium alloy. It is also important to consider other factors, such as the alloy's microstructure and the presence of impurities, which can affect its performance in aerospace applications.