Reverse martensitic transformation in alumina–15vol% zirconia nanostructured powder synthesized by high energy ball milling

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

“…The experiments were designed to evaluate three distinct types of commercially available zirconia toughened alumina namely: (i) alumina-15 vol% zirconia, [7] (Fritsch Pulverisette-6, Idar Oberstein, Germany). Some characteristic properties of as received powders are shown in Table 1, more details about starting materials can be found elsewhere [7].…”

“…Some characteristic properties of as received powders are shown in Table 1, more details about starting materials can be found elsewhere [7]. At different HEBM time (1 h, 5 h and 10 h) a little amount of powder was taken out and HEBM-ed powders were compacted into a cylindrical die (10 mm in diameter at 2:1 ratio of diameter to height) by a pressure of 100 MPa (Amsler, Schaeehous, Switzerland).…”

“…In this respect, we have shown [7] the enhancement of high energy ball milling (HEBM) on phase transformation of monoclinic (m) to tetragonal (t) in alumina-zirconia nanocomposite powder. In another word, reverse martensitic transformation could be greatly enhanced by HEBM which literally reinforces the structure.…”

Solid state and liquid phase sintering of mechanically activated W–20wt.% Cu powder mixture

“…At different stages of milling (5,10,15,20,40, 60, 80 and 100 h), small batch of the milled powder was taken out of the vessel for testing. The characteristics of the powders were exam- ined by different methods including: particle morphology by scanning electron microscopy (Philips XL30 SEM and TSCAN VEGA II XMU, Czech Republic); particle size distribution by laser particle size analyzer (Mastersizer 2000, Malvern Instruments); powder density by standard Hall method (ASTM Standard B 417 and MPIF 28); microstructure by optical and electron microscopy (SEM and field-emission TEM, Philips CM200-FEG); chemical analysis by inductive coupled plasma spectroscopy (ICP, Jobin Yvon Emission, JY 138, Edison, New Jersey, USA), atomic absorption spectroscopy (AAS, Varian Techtron AA6, Mulgrave, Victoria, Australia) and energy dispersive X-ray (EDX); crystallite size and lattice strain by X-ray diffraction according to Williamson-Hall method [22][23]; phase transformation by differential thermal analysis (DTA Netzsch STA 409PC/PG, Burlington, MA, USA).…”

High-Energy Milling

“…Pure ZrO 2 is a material that can suffer a martensitic transformation, i.e. tetragonal to monoclinic phase transformation that induces a cracking phenomenon on cooling from the fabrication temperature [16]. The addition of dopants such as Al 2 O 3 and MgO are known to stabilize the tetragonal structure at room temperature.…”