Effects of heat treatment temperature on microstructure and mechanical properties of lithium disilicate-based glass-ceramics

2018 ◽  
Vol 44 ◽  
pp. S121-S124 ◽  
Author(s):  
Manlika Kamnoy ◽  
Kamonpan Pengpat ◽  
Uraiwan Intatha ◽  
Sukum Eitssayeam
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Heat Treatment Temperature ◽  
Glass Ceramics ◽  
Lithium Disilicate ◽  
Treatment Temperature ◽  
Microstructure And Mechanical Properties

scholarly journals Evolution of Microstructure and Mechanical Properties of Nanostructured NiFe Films under Influence of Heat Treatment

2021 ◽  
Vol 20 (2) ◽  
pp. 109-120
Author(s):  
V. M. Fedosyuk
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Grain Size ◽  
Surface Layer ◽  
Young’S Modulus ◽  
Heat Treatment Temperature ◽  
Young's Modulus ◽  
Treatment Temperature ◽  
Microstructure And Mechanical Properties ◽  
Internal Volume

. Nanostructured NiFe films were synthesized by pulsed electrolytic deposition on silicon with a gold sublayer, after which they have been subjected to to temperature treatment at 373-673 K in order to study the effect of heat treatment on the microstructure and mechanical properties of the objects under study. High-resolution atomic force microscopy has made it possible  to trace the stages of  microstructure evolution under the  influence of  heat treatment, including the process of  nonlinear increase in grain growth and two-stage agglomeration. It is shown that with an increase in heat treatment temperature to 673 K, the grain size increases from 68 to 580 nm in comparison with the initial sample, undergoing agglomeration processes at temperatures of  100 and 300 °C. The mechanical properties of nanostructured NiFe films have been studied by the nanoindentation method. The dependences of the hardness of Young’s modulus and the values of the resistance to elastoplastic deformation on depth have been obtained and analyzed in the paper. This approach has permitted to reveal differences in the behavior of the mechanical properties of the surface layer and the internal volume of the film under the action of different heat treatment temperatures, as well as to demonstrate the opposite reaction of different material layers to an increase in temperature. As a result of a thorough analysis of the deformation curves of nanoindentation, it has been found that the homogenization of the surface in combination with the activation of oxidation processes leads to the strengthening of near-surface layer of NiFe films. At the same time, the internal volume of the material is characterized by a nonlinear decrease in hardness and Young’s modulus with an increase in the heat treatment temperature. The explanation for this phenomenon has been found in the complex effect of a decrease in the number of grain boundaries (due to an increase in the average grain size with increasing temperature) and an increase in the concentration of gold atoms diffusing from the sublayer more actively with an increase in the processing temperature of NiFe films.

Lead titanate glass-ceramics derived from a silicate-based melt

2005 ◽  
Vol 20 (5) ◽  
pp. 1316-1323 ◽  
Author(s):  
P. Sooksaen ◽  
I.M. Reaney ◽  
D.C. Sinclair
Keyword(s):  
Heat Treatment ◽  
Heat Treatment Temperature ◽  
Crystal Size ◽  
Finite Size ◽  
Glass Ceramics ◽  
Treatment Temperature ◽  
Finite Size Effects ◽  
Peak Broadening ◽  
Permittivity Measurements ◽  
Nano Size

Glass composition 39PbO–1BaO–25TiO2–9.8Al2O3–24.2SiO2–1B2O3 (mol%) crystallized on heat treatment at ≥600 °C to form glass-ceramics whose majority phase was PbTiO3 (PT). At 600 °C, nano-size PT crystals (∼20–50 nm) with a c/a ratio of 1.000(1) were observed, but as heat-treatment temperature increased to 1000 °C, the crystal size and c/a ratio increased to ∼1.2 μm and 1.056(4), respectively. Permittivity measurements as a function of temperature revealed a broad peak at ∼400 °C associated with the nanocrystalline PT crystals, but it sharpened and increased in temperature as heat treatment temperature increased to 1000 °C. The causes of peak broadening and shift of Tc are believed to be due to either clamping of PT crystals by glass matrix, finite size effects due to their intrinsically small size, or the incorporation of dopant impurities such as Al, Si, or Ba ions in the PT phase.

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