Improving adhesive strength of WC-CoCr coating with novel bimodal roughening substrate: Finite element modeling. Issue 8 (1st June 2020)

• Record Type: Journal Article
• Authors: Tahir, Adnan; Li, Guang-Rong; Wei, Zhi-Yuan; Liu, Mei-Jun; Yang, Guan-Jun; Li, Chang-Jiu
• Is Part Of: Ceramics international. Volume 46:Issue 8(2020)Part A
• Page Start: 10481
• Page End: 10489
• Publication Date: 2020-06-01
• Subjects: Adhesive strength -- Bimodal roughness -- Durability -- Interfacial crack -- FEM -- Residual stress; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2020.01.047
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: The durability of a coating-substrate system is mainly determined by its adhesion strength. However, a major challenge is to effectively evaluate the adhesive effect after design, as measuring the adhesion strength of complex composite coatings is difficult. In this work, a bi-roughened surface of substrate was designed and its effects on the adhesive strength of WC-CoCr coatings were explored by simulation. Initially, a finite element model was established to simulate the substrate-coating system with bi-roughening (sub-roughness and sub-roughening angles) interface. In the case of monomodal Ra 7.5 μm, the adhesive strength was predicted to be only 68 MPa. While, the designed sub-roughening of Ra 0.8 μm enhanced the value to nearly 80 MPa. Moreover, the adhesive strength is further improved to above 100 MPa by tailoring the sub-roughening angle to 60°. The residual stresses along interfacial region decrease significantly for bi-roughening design, which can be responsible for enhanced adhesive strength. Additionally, individual crack growth occurs in almost every bi-roughening, and does not connect with the main crack, which result in a proportional increase in apparent interfacial shear strength. Briefly, adhesion strength is considerably improved for the bi-roughening design, which is beneficial for durability of the coatings during service.