An Ultimate Guide to Titanium Alloy Types

Titanium alloys are revered for their exceptional strength-to-weight ratio, corrosion resistance, and biocompatibility, making them indispensable across aerospace, medical, automotive, marine, and energy industries.

Classification by Crystal Structure

Titanium alloys fall into four main categories based on their microstructure, each suited to different applications:

α-Alloys
Contain neutral or α-stabilizing elements (e.g. Sn, Al, O).
Non-heat-treatable; excellent weldability and resistance to high temperatures (~550 °C).

Near-α Alloys
Primarily α-phase with minor β-stabilizers (Mo, Si, V).
Good creep resistance and moderate strength (e.g., Ti-6Al-2Sn-4Zr-2Mo).

α+β (Metastable) Alloys
Balanced mix of α and β phases (e.g., Ti-6Al-4V, Grade 5/TC4).
Widely used due to customizable properties through heat treatment.

Β-Alloys
Rich β-stabilizers (Mo, V, Nb, etc).
Fully heat-treatable, high strength, flexible formability; common in spring/structural applications.

Titanium Alloy Grades & Applications

Here’s an overview of key grades and their characteristics:

Choosing the Right Alloy

Corrosion-critical & formable? → Commercially pure (Grades 1–4).

Maximum strength & light weight? → Grade 5 (Ti-6Al-4V), the "workhorse" alloy.

Medical implants? → Grade 23 (ELI) for superior toughness.

High-temp & structural use? → α or near-α alloys (e.g., Grade 6, 38).

High fatigue/formability? → β or metastable β alloys (e.g., Grade 15-3-3-3, Beta-C).

Summary

α-Alloys (Grades 1–4, 6): Optimal for corrosion resistance, weldability, moderate heat.

α+β-Alloys (Grades 5, 9, 23, 38): Best all-rounders, with high strength, ductility, and tunable through heat treatment.

β-Alloys (15-3-3-3, Beta-C, Grade 19): Excel in strength, fatigue life, and formability for cyclic and structural applications.

Understand your needs: corrosion, strength, fatigue, temp range, formability.

Pick the right category: α, α+β, or β, tailored to application conditions.

Consider specialized grades for medical (ELI), aerospace (Grade 5/9), or high-temp use (Grade 6, 38).