Synthesis, crystal structure, microstructure and mechanical properties of (Ti1-xZrx)3SiC2 MAX phase solid solutions. Issue 1 (January 2019)

• Record Type: Journal Article
• Authors: Qu, Lianshi; Bei, Guoping; Stelzer, Bastian; Rueß, Holger; Schneider, Jochen M.; Cao, Dianxue; van der Zwaag, Sybrand; Sloof, Willem G.
• Is Part Of: Ceramics international. Volume 45:Issue 1(2019)
• Page Start: 1400
• Page End: 1408
• Publication Date: 2019-01
• Subjects: MAX phases -- (Ti1-xZrx)3SiC2 -- Solid solution -- Crystal structure -- Mechanical properties; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2018.10.030
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Almost pure (Ti1- x Zr x )3 SiC2 MAX phase solid solutions with x ranging up to 0.17 were synthesized at temperatures in the range of 1450–1750 °C with reactive Spark Plasma Sintering (SPS). The zirconium partially replaces the M-element titanium of the Ti3 SiC2 MAX phase up to x equals 0.17. The lattice parameters of the hexagonal (Ti1- x Zr x )3 SiC2 MAX phase are determined with X-ray diffraction using Rietveld refinement and show an anisotropic lattice expansion upon Zr insertion into Ti3 SiC2 . This observation is in very good agreement with density functional theory calculations where the deviation between the measured and calculated lattice parameter is less than 1%. The predicted elastic modulus reduction is only 4%. This behavior can be rationalized by considering the electronic structure, where only minute changes are observable as Zr is incorporated into Ti3 SiC2 . The measured nanohardness of the synthesized (Ti1- x Zr x )3 SiC2 MAX phase increases from 12.7 ± 1 GPa for Ti3 SiC2 to 16.3 ± 1.1 GPa when x is raised from 0 to 0.17 due to an increasing amount of accompanying Ti1- y Zr y C. The elastic moduli of (Ti1- x Zr x )3 SiC2 solid solutions measured by an ultrasonic pulse-echo method (325–354 GPa) are in good agreement with the predicted elastic moduli (357–342 GPa).