Crystallographic features of a variants and ß phase for Ti-6Al-4V alloy fabricated by selective laser melting
Abstract
The present study investigated the crystallographic features of α variants and β phase for Ti-6Al-4V alloy fabricated by selective laser melting. Theβ fiber texture parallel to the building direction was ascertained on the basis of a reconstruction method realized by the manipulation of stereographic projection. The SLMed alloy has no α/α′ variants selection but contains a special crystallographic area exhibiting random orientation which cannot be reconstructed as a parental columnar β grain with the present introduced method due to its nature as the overlapped area between adjacent melt pools resulting from the heterogeneous nucleation in front of the liquid-solid interface. With increasing the heat treated temperature, α variants selection occurs. Especially at higher temperature of 905 °C, the intergranular β phase following a reversed crystallographic path as “parental β phase”→“α variants”→“intergranular β phase” would be precipitated, therefore the intergranular β phase keeps the same orientation with the parental β phase. Once the alloy was heat treated at 975 °C close to Tβ, the microstructure is characterized by primary α variants selection and a large amount of secondary α widmanstatten structure with a homogeneous orientation which accounts for the lowest tensile strength. The decomposition of twelve α variants proved the BORβ//(0001)α,β//α. The misorientation between two variants sharing a common parentalβ pole with a similar color consisting of all Euler angles was identified to be [0001] α/10.53°.
RAS ID
26970
Document Type
Journal Article
Date of Publication
2017
Location of the Work
Netherlands
School
School of Science
Copyright
subscription content
Publisher
Elsevier
Comments
Yang, Y., Chen, J., Wang, H. L., Zhang, Z. Q., Lu, Y. J., Wu, S. Q., & Lin, J. X. (2017). Crystallographic features of α variants and β phase for Ti-6Al-4V alloy fabricated by selective laser melting. Materials Science and Engineering: A, 707, 548-558. https://doi.org/10.1016/j.msea.2017.09.068