TY - JOUR
T1 - Comparative study on process-structure-property relationships of TiC/Ti6Al4V and Ti6Al4V by selective laser melting
AU - Jiang, Qinghong
AU - Li, Shuai
AU - Guo, Sai
AU - Fu, Mingwang
AU - Zhang, Bi
N1 - Funding Information:
This work was supported by Shenzhen Science and Technology Innovation Commission for the project numbered JSGG20210420091802007 , and the project of GRF No. 15228621, ZE1W and 1-CD4H from PolyU. The authors also wish to acknowledge the assistance from SUSTech Core Research Facilities.
Publisher Copyright:
© 2022
PY - 2023/3/1
Y1 - 2023/3/1
N2 - Titanium matrix composites (TMCs) have gained tremendous attention due to their excellent mechanical properties by combining the advantages of Ti6Al4V matrix and ceramic reinforcement. In current study, the selective laser melting (SLM) technique is applied to manufacture TiC/Ti6Al4V and Ti6Al4V. Systematic characterization and analysis are conducted to reveal and compare their process-structure-property relationships. The results reveal that the near fully dense parts could be manufactured by process optimization upon the systematic investigation on their densification behaviors. The addition of TiC effectively refines the matrix grain and changes the microstructures. The SLM-manufactured (SLM-ed) Ti6Al4V exhibits typical coarse columnar grains with ultrafine lamellar α+β microstructures distributed inside (average α-lath thickness: 282 nm). Nevertheless, the SLM-ed TMCs possess a peculiar molten pool morphology, in which the sub-columnar grains grow upward along the direction of the steepest temperature gradient. The acicular nanoscale TiC is dispersed inside the sub-columnar grains, while the chain-like TiC is distributed along the boundary. Meanwhile, an evolution process is proposed to describe the microstructure evolution of the SLM-ed TMCs. The interrelationships between energy density and resulting microstructures are also identified, based on which, strong and ductile Ti6Al4V specimens (tensile strength: 1390 MPa, elongation: 9.66%) and ultra-strong TMCs specimens (tensile strength: 1538 MPa) are manufactured. The strengthening effects are mainly attributed to the Hall-Petch strengthening and load-bearing transformation. Fracture analysis indicates that the failure of the SLM-ed Ti6Al4V is caused by the micro-voids nucleation and coalescence at the interface of α and β phases, whereas the premature fracture of the SLM-ed TMCs is originated from the chain-like TiC.
AB - Titanium matrix composites (TMCs) have gained tremendous attention due to their excellent mechanical properties by combining the advantages of Ti6Al4V matrix and ceramic reinforcement. In current study, the selective laser melting (SLM) technique is applied to manufacture TiC/Ti6Al4V and Ti6Al4V. Systematic characterization and analysis are conducted to reveal and compare their process-structure-property relationships. The results reveal that the near fully dense parts could be manufactured by process optimization upon the systematic investigation on their densification behaviors. The addition of TiC effectively refines the matrix grain and changes the microstructures. The SLM-manufactured (SLM-ed) Ti6Al4V exhibits typical coarse columnar grains with ultrafine lamellar α+β microstructures distributed inside (average α-lath thickness: 282 nm). Nevertheless, the SLM-ed TMCs possess a peculiar molten pool morphology, in which the sub-columnar grains grow upward along the direction of the steepest temperature gradient. The acicular nanoscale TiC is dispersed inside the sub-columnar grains, while the chain-like TiC is distributed along the boundary. Meanwhile, an evolution process is proposed to describe the microstructure evolution of the SLM-ed TMCs. The interrelationships between energy density and resulting microstructures are also identified, based on which, strong and ductile Ti6Al4V specimens (tensile strength: 1390 MPa, elongation: 9.66%) and ultra-strong TMCs specimens (tensile strength: 1538 MPa) are manufactured. The strengthening effects are mainly attributed to the Hall-Petch strengthening and load-bearing transformation. Fracture analysis indicates that the failure of the SLM-ed Ti6Al4V is caused by the micro-voids nucleation and coalescence at the interface of α and β phases, whereas the premature fracture of the SLM-ed TMCs is originated from the chain-like TiC.
KW - Process-structure-property relationship
KW - Selective laser melting
KW - Ti6Al4V titanium alloy
KW - Titanium matrix composites
UR - http://www.scopus.com/inward/record.url?scp=85143124296&partnerID=8YFLogxK
U2 - 10.1016/j.ijmecsci.2022.107963
DO - 10.1016/j.ijmecsci.2022.107963
M3 - Journal article
AN - SCOPUS:85143124296
SN - 0020-7403
VL - 241
JO - International Journal of Mechanical Sciences
JF - International Journal of Mechanical Sciences
M1 - 107963
ER -