Quantitative Relationships between Mechanical Properties and Microstructure of Ti17 Alloy after Thermomechanical Treatment

In this paper, the relationships between the thermomechanical treatments (TMT), the microstructural evolution the mechanical properties of Ti17 alloy were investigated. The results indicate the coarsening behavior of lamellar alpha was sensitive to the aging temperature during the process of TMT. The thickness of lamellar alpha changed from 0.19 to 0.38 mu m with an increase in the aging temperature. Moreover, both tensile properties and impact toughness vary with the thickness of lamellar alpha. The tensile strength increases with the increase of the thickness of lamellar alpha the plasticity and impact toughness the opposite trend. The quantitative investigations found that there is a linear relationship between the tensile properties and the thickness of lamellar alpha the tensile properties could be adjusted in the range of 1191 similar to 1062 MPa and 1163 similar to 1039 MPa to obtain ultimate tensile strength and yield strength as well as 11 similar to 16% elongation and 23 similar to 33% reduction of area by varying the thickness of lamellar alpha. Meanwhile, the impact toughness could be adjusted in the range of 46 similar to 53 J/cm(2). The high correlation coefficients imply that the linear equation is reliable to describe the relationships between the mechanical properties and the thickness of lamellar alpha for Ti17 alloy.