Fabrication and characterization of (Mg1−xFex)O (0.05≤x≤0.25) ceramics. Issue 2 (March 2015)

• Record Type: Journal Article
• Authors: Li, Shengli; Qin, Xiaoying; Li, Yuanyue; Song, Chunjun
• Is Part Of: Ceramics international. Volume 41:Issue 2(2015)Part A
• Page Start: 2565
• Page End: 2571
• Publication Date: 2015-03
• Subjects: C. Mechanical properties -- C. Thermal properties -- (Mg1−xFex)O ceramics -- Chemical preparation; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2014.11.002
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Highly dense (Mg1− x Fe x )O (0.05≤ x ≤0.25) ceramics (relative density >98%) were prepared by ultrasonic assisted oxalate co-precipitation method together with spark plasma sintering. Mechanical measurements indicate that Young's modulus decreases monotonously from 312 to 268.5±5.2 GPa with increasing Fe content x from 0 to 0.25. In contrast, the Vickers hardness first increases from 6.8 to 8.50±0.11 GPa as x increases from 0 to 0.1, and then decreases monotonously with further increasing x . The increase and decrease in the hardness with x can be mainly attributed to the solid solution strengthening and weakening of Peierls–Nabarro stress, respectively. Thermal analyses reveal that heat capacity C p decreases (from 0.896±0.018 to 0.816±0.016 (J K) −1 g −1 at 323 K, for instance) with increasing x (from 0.05 to 0.25) due to the lower C p of FeO. Similarly, thermal conductivity κ of the samples decreases (say, from 24.8±1.0 to 3.7±0.1 (W K) −1 m −1 at 323 K) with the increasing x (from 0.05 to 0.25), which could be ascribed to the decreasing melting point and increasing mean atomic weight resulting from substitution of Mg for Fe.