Titanium is a popular transitional metal with the appearance of hard, shiny and strong. Pure titanium (also known as commercially pure titanium) is characterized by light weight, high strength, high ductility and resistance to  marine and chlorine corrosion. These characteristics make titanium a highly sought metal for the creation of a countless number of products. It is widely used in aviation industry, marine industry, chemical industry, machine parts, and much more. In addition to commercially pure titanium, the titanium market relies on the use of various titanium alloys. Titanium alloy is an alloy consisting primarily of pure titanium with other various metals or chemical elements distributed throughout. When titanium mixed with other metals and chemical elements, titanium alloy offers increased tensile strength and toughness (even at extreme temperatures) while maintaining the advantage of titanium's unique qualities. With their excellent properties, titanium alloys can be used for the most challenging applications, such as airframe parts (the most critical and highly-stressed part in aircrafts), for both civilian and military aircrafts.

Classifications of Titanium Alloys

Commercially pure titanium only includes several distinct grades of products. However, titanium alloys can be divided into alpha alloys, near-alpha alloys, beta and near-beta alloys, and alpha-beta alloys according to their structure. According to their strength, they also can be divided into low strength alloys, moderate strength alloys, medium strength alloys, high strength alloys, and very high strength alloys. The most common way to classify titanium alloys is by their structure, so here is a brief introduction for alpha alloys, near-alpha alloys, beta and near-beta alloys, and alpha- beta alloys.

• Alpha alloys: Alpha alloys contain neutral-alloying elements, as well as alpha stabilizers (aluminum, oxygen, etc.). These alloys are not heat treatable as they are single-phase alloys. Good strength and weldability and great oxidation resistance are their dominant characteristics. Their primary users are in chemical and engineering industries.
• Near-alpha alloys: Compared to alpha alloys, near-alpha alloys contain 1-2% of beta-phase stabilizers (most commonly these are silicon, vanadium or molybdenum), which increase their overall ductility. Near-alpha alloys are the most common high-temperature alloys and their maximum working temperature is to 500 to 550 °C.
• Beta and near-beta alloys: These alloys contain sufficient beta stabilizing element (such as molybdenum, silicon and vanadium) to allow them to maintain the beta phase when quenched. They have excellent formability, and can achieve high strength by heat and solution treated. These alloys are often seen in orthodontic applications, having replaced stainless steel.
• Alpha-beta alloys: Just as their name, alpha-beta alloys generally include some combination of both alpha and beta stabilisers. These alloys can be strengthened by solution treating and aging, and provide medium to high strength with tensile strengths ranging from 620 to 1250 MPa and creep resistance ranging from 350 to 400 °C. These alloys are great candidates for aerospace applications.