Plasma sprayed graphene/carbon nanotube reinforced lanthanum-cerate hybrid composite coating. Issue 7 (1st April 2023)

• Record Type: Journal Article
• Authors: Singh, Pushpender; Islam, Aminul; Pandit, Niranjan; Indupuri, Satish; Rahman, O.S. Asiq; Pandey, Shailesh Mani; Keshri, Anup Kumar
• Is Part Of: Ceramics international. Volume 49:Issue 7(2023)
• Page Start: 11167
• Page End: 11177
• Publication Date: 2023-04-01
• Subjects: Lanthanum cerate -- Plasma spray coating -- Mechanical property -- Toughness -- Thermal shock resistance; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2022.11.313
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Lanthanum cerate (LC: La2 Ce2 O7 ) is a potential material for thermal barrier coating, whose improved toughness is a crucial necessity for the pathway of its industrialization. Herein, we demonstrated a promising approach to develop graphene/carbon nanotube hybrid composite coating using a large throughput and atmospheric plasma spraying method. Graphene nanoplatelets (GNP: 1 wt %) and carbon nanotube (CNT: 0.5 wt %) reinforced lanthanum cerate (LCGC) hybrid composite coatings were deposited on the Inconel substrate. Addition of 1 wt % GNP and 0.5 wt % CNT in LC matrix has significantly increased its relative density, hardness, and elastic modulus up to 97.2%, 2–3 folds, 3–4 folds, respectively. An impressive improvement of indentation toughness (8.04 ± 0.2 MPa m 0.5 ) was observed on LCGC coating, which is ∼8 times higher comparing the LC coating. The toughening was attributed to the factors: such as the distribution of GNPs and CNTs in the LC matrix, synergistic toughening offered by the GNPs and CNTs; (i) GNP/CNT pull-out, (ii) crack bridging and arresting, (iii) splat sandwiching, mechanical interlocking, etc. Finally, this improved toughness offered an exceptional thermal shock performance up to 1721 cycles at 1800 °C, without any major failure on the coating. Therefore, the GNP and CNT-reinforced LC hybrid composite coating can be recommended to open a path for turbine industries.