Effect of hot isostatic pressing on microstructure and mechanical properties of Ti6Al4V-zirconia nanocomposites processed by laser-powder bed fusion

• Published in: Materials & design Vol. 214; p. 110392
• Main Authors: Hattal, Amine, Mukhtarova, Kamilla, Djemai, Madjid, Chauveau, Thierry, Hocini, Azziz, Fouchet, Jean Jacques, Bacroix, Brigitte, Gubicza, Jenő, Dirras, Guy
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2022; Elsevier
• Subjects: Hot isostatic pressing; Laser powder bed fusion; Mechanical properties; Titanium alloys; Zirconia; Zirconia; Mechanical properties; Titanium alloys; Laser powder bed fusion; Hot isostatic pressing
• ISSN: 0264-1275; 1873-4197
• DOI: 10.1016/j.matdes.2022.110392

[Display omitted] •HIP post-treatment was performed on L-PBF fabricated Ti64 reinforced with nYSZ ceramic.•HIP post-treatment was successful in increasing the relative density of reinforced parts.•HIP processing parameters prevented β phase formation in reinforced parts.•HIP post-treatment generated thick α grains and homogeneous microstructure.•HIP post-treatment increased the plastic deformation of all parts without drastic strength decrease. This study discusses the effects of hot isostatic pressing (HIP) post-treatment on Laser Powder Bed Fusion of Ti6Al4V and Ti6Al4V reinforced with 1 wt% and 2.5 wt% of nano-yttria-stabilized zirconia (nYSZ). The bulk parts display a higher density after HIP post-treatment than the as-built counterparts. Besides, X-ray diffraction (XRD) analysis indicates a reduction of the β phase percentage after HIP. An increase in α grain thickness is noticed on both reinforced and unreinforced parts. Additionally, compared to their un-HIPed counterparts, the microhardness decreases after HIP post-treatment by 3%, 11%, 8% and 4% for the as-built Ti6Al4V, stress relieved Ti6Al4V, 1 wt% nYSZ reinforced and 2.5 wt% nYSZ reinforced parts, respectively. The same trend was observed for the yield stress, which decreases by 1%, 4% and 8%, for the as-built Ti6Al4V, stress relieved Ti6Al4V and 2.5 wt% nYSZ-reinforced parts respectively after HIP post-treatment, except for 1 wt% nYSZ-reinforced part, whose yield stress increase by about 7%, which could be attributed to the specific texture evolution within this material. The plastic strain was significantly enhanced after HIP in all materials.