1. What Tensile Strength Means
Tensile strength is the maximum stress a material can withstand under tension before it fractures. For titanium plates it is reported with the yield strength and elongation on the mill certificate, and it is the primary mechanical property used to select the grade for structural applications. The tensile strength of titanium depends mainly on the grade and the processing history.
2. Commercial Pure Grades
Commercial pure titanium grades are classified by the interstitial content, mainly oxygen and iron, which controls the strength. Grade 1 has a minimum tensile strength of about 240 MPa, grade 2 about 345 MPa, grade 3 about 440 MPa and grade 4 about 550 MPa. Higher grades are stronger but less formable, so the choice balances strength against fabricability and corrosion resistance.
3. Titanium Alloy Grades
Titanium alloys reach much higher tensile strength. The workhorse alloy Ti-6Al-4V has a minimum tensile strength of about 895 MPa in the annealed condition, and heat-treated alloys can exceed 1,000 MPa. Alpha-beta and beta alloys are selected where high strength-to-weight is required, such as aerospace structures, while the alloying additions also affect toughness and temperature capability.
4. Factors That Affect the Strength
Composition: interstitial oxygen and iron raise the strength of pure grades; alloying elements raise it further.
Processing: rolling direction, reduction and annealing set the microstructure.
Heat treatment: solution treatment and aging increase the strength of alloys.
Temperature: strength falls at elevated temperature, so the service temperature must be considered.
5. Selecting the Grade
The grade is selected by the strength requirement, the operating temperature, the corrosion environment and the fabrication method. For chemical and marine service, a commercial pure grade is usually sufficient; for aerospace and high-load structural work, an alloy grade is required. The mill certificate should state the tensile strength, yield strength and elongation of the delivered batch.
6. FAQ
Q1: What is the tensile strength of titanium plate? It ranges from about 240 MPa for grade 1 pure titanium to more than 895 MPa for Ti-6Al-4V alloy.
Q2: Which grade is strongest? Alloy grades such as Ti-6Al-4V are far stronger than commercial pure grades.
Q3: How is tensile strength verified? By the mill certificate and, when required, by testing a sample from the batch.
Q4: Does heat treatment increase strength? Yes, solution treatment and aging raise the strength of titanium alloys significantly.
Q5: Which grade should I choose? Match the grade to the strength, temperature, corrosion and fabrication requirements of the application.
Q6: What is reported on the certificate? Tensile strength, yield strength and elongation, together with the composition and grade.
