Effect of sintering on structure and mechanical properties of alumina–15 vol% zirconia nanocomposite compacts

• Published in: Journal of alloys and compounds 2010-03, Vol.493 (1), p.613-618
• Main Authors: Maneshian, Mohammad H., Banerjee, Malay K.
• Format: Article
• Language: English
• Subjects: Alumina–zirconia nanocomposite; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; High energy ball milling; Materials science; Materials synthesis; materials processing; Mechanical properties; Physics; Sintering
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2009.12.166

The sintering and densification behavior of high energy ball milled (HEBM-ed) alumina–15 vol% zirconia nanocomposite were carried out and the probable tetragonal to monoclinic phase transformation of ZrO 2 during sintering was investigated. Evolution of microstructure resulting from sintering was followed up by means of scanning electron microscopy (SEM) on polished samples, and the degree of phase transformation was determined by quantitative X-ray analysis (XRD). Moreover, synergetic effect of milling time and dopant composition on properties such as relative density, hardness, and fracture toughness was studied. The results have shown that mechanical properties of the composites were strongly dependent on the dopant content, structure and the fraction of tetragonal to monoclinic induced by HEBM and subsequent sintering. The extent of retention of t-ZrO 2 depends on the balance of magnitude of the strain energy arising from HEBM and releasing from sintering. In fact, compacts with aggressive HEBM history showed improved fracture toughness. Also it is shown the homogeneous microstructure obtained by HEBM and subsequent sintering promotes better densification.