Effects of Cr2O3 addition on the phase, mechanical properties, and microstructure of zirconia-toughened alumina added with TiO2 (ZTA–TiO2) ceramic composite. (December 2016)

• Record Type: Journal Article
• Authors: Manshor, Hanisah; Azhar, Ahmad Zahirani Ahmad; Rashid, Rashita Abd; Sulaiman, Shazreen; Abdullah, Ezzat Chan; Ahmad, Zainal Arifin
• Is Part Of: International journal of refractory metals & hard materials. Volume 61(2016:Dec.)
• Page Start: 40
• Page End: 45
• Publication Date: 2016-12
• Subjects: ZTA-TiO2 ceramics composite -- Cr2O3 -- Vickers hardness -- Fracture toughness; Heat resistant alloys -- Periodicals; Refractory materials -- Periodicals; Metallography -- Periodicals; Alliages réfractaires -- Périodiques; Matériaux réfractaires -- Périodiques; Métallographie -- Périodiques; Heat resistant alloys; Metallography; Refractory materials; Periodicals; Electronic journals; 669.73
• DOI: 10.1016/j.ijrmhm.2016.08.005
• Languages: English
• ISSNs: 0263-4368

Abstract

Abstract: Increasing demand for stronger cutting tools has led to the development of several novel composites and other multi-phase ceramics with better properties, particularly high fracture toughness. Cr2 O3 is used as new material additive in this study, as it has attracted attention due to the formation of isovalent solid solution when added to Al2 O3, contributing to improved fracture toughness. Thus, the aim of this study is to investigate the effects of the addition of Cr2 O3 at a concentration of between 0.0 wt% to 1.0 wt% on the physical properties, microstructural features and phase of a ZTA-TiO2 ceramics composite. The samples were prepared by wet-mixing and uniaxial compaction, then sintered for 1 h at 1600 °C under pressureless conditions. The sintered samples were then identified in terms of their density, hardness, fracture toughness and crack propagation, and were then subjected to microstructural analysis by XRD and FESEM. It was discovered that with addition of 0.6 wt% of Cr2 O3 to the composite, an optimum density of 4.0630 g/cm 3, hardness of 1681 HV, and fracture toughness of 7.15 MPa.m 1/2 were obtained. As a result of this addition, plate-like Al2 O3 grains were observed, which caused cracks formed in the composite to spread in an inter-granular manner. This confirmed that the properties of ZTA–TiO2 ceramics composite were augmented by the addition of 0.6 wt% Cr2 O3 . Highlights: Effects of Cr2 O3 addition on the ZTA-TiO2 systems were investigated. Small additions of Cr2 O3 lead to improved mechanical properties. The formation of isovalent solid solution when Cr2 O3 added to Al2 O3, contributing to improved fracture toughness.