Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1578908 | Materials Science and Engineering: A | 2011 | 5 Pages |
The uniaxial tensile properties of metallic materials can be determined by representing the indentation stress and strain by the load/depth parameters from instrumented indentation tests using a spherical indenter. Here we propose a modified algorithm for evaluating the tensile properties of Ti alloys with low E/σy values by taking into account the plastic constraint effect in low-strain regions. The ratio of elastic modulus to yield strength, E/σy, can be interpreted as a measure of the amount of deformation plastically accommodated during indentation. For low E/σy materials, deformation is elastic-dominated, so less constraint occurs than in high E/σy materials. Finite element methods and spherical indentation tests were used to explore the constraint effect for a variety of materials characterized by different E/σy. The constraint factors were plotted as (E/σy)(a/R) based on expanding cavity model. The modified approach was experimentally verified by comparing tensile properties from uniaxial tensile test and instrumented indentation tests.
► We propose a modified representation method for Ti alloys. ► Less constraint occurs for Ti alloys due to low E/σy value. ► The plastic constraint factor of Ti alloys is plotted as (E/σy)(a/R). ► The yield and tensile strength obtained are within ±10% of those from tensile tests.