THERMAL STABILITY OF NANOCRYSTALLINE COPPER FILMS

The grain growth kinetics of nanocrystalline copper thin film samples was investigated. The grain size of nanocrystalline copper samples was determined from the broadening of X-ray spectra. It was found that the grain size increased linearly with isothermal annealing time within the first 10 minutes, beyond which power-law growth kinetics is applied. The activation energy for grain growth was determined by constructing an Arrhenius plot, which shows an activation energy of about 21 – 30 kJ/mol. The low activation energy is attributed to the second phase particle drag and the porosity drag, which act as the pinning force for grain growth in nanocrystalline copper.

Download Full-text

Grain Growth in Nb-Alloyed Stainless Steel of AISI 347 during Heating

Materials Science Forum ◽

10.4028/www.scientific.net/msf.753.345 ◽

2013 ◽

Vol 753 ◽

pp. 345-348 ◽

Cited By ~ 1

Author(s):

Hai Wen Luo ◽

Han Dong ◽

Ling Feng Chen

Keyword(s):

Activation Energy ◽

Stainless Steel ◽

Grain Growth ◽

Growth Kinetics ◽

Isothermal Holding ◽

Growth Exponent ◽

Microalloyed Steels ◽

Nb Content ◽

Grain Growth Kinetics ◽

Kinetics Of

Grain growth kinetics in an AISI 347 stainless steel with Nb content up to 0.7%wt was studied during the isothermal holding in the temperature range of 1100-1270°C for various periods. Abnormal grain growth was observed even in the presence of a large amount of precipitates. The kinetics of normal grain growth was tracked by metallographic measurements and fitted by the classical modeling, which led to two important parameters of activation energy Q and growth exponent n derived. Both of them are larger than the usual values for grain growth in the Nb-microalloyed steels due to the much larger content of Nb in the present steel.

Download Full-text

Drag Effects of Solute and Second Phase Distributions on the Grain Growth Kinetics of Pre-Extruded Mg-6Zn Alloy

Journal of Material Science and Technology ◽

10.1016/j.jmst.2016.06.025 ◽

2016 ◽

Vol 32 (12) ◽

pp. 1260-1266 ◽

Cited By ~ 12

Author(s):

Zhaoyang Jin ◽

Donghua Yu ◽

Xintong Wu ◽

Kai Yin ◽

Kai Yan

Keyword(s):

Grain Growth ◽

Growth Kinetics ◽

Second Phase ◽

Grain Growth Kinetics ◽

Kinetics Of

Download Full-text

Grain growth kinetics for B2O3-doped ZnO ceramics

Materials Science-Poland ◽

10.1515/msp-2015-0029 ◽

2015 ◽

Vol 33 (2) ◽

pp. 220-229 ◽

Cited By ~ 5

Author(s):

Berat Yuksel ◽

T. Osman Ozkan

Keyword(s):

Activation Energy ◽

Grain Growth ◽

Growth Kinetics ◽

Liquid Phase Sintering ◽

Growth Exponent ◽

Second Phase ◽

Growth Activation ◽

Doped Zno ◽

Grain Growth Kinetics ◽

Zno Ceramics

AbstractGrain growth kinetics in 0.1 to 2 mol % B2O3-added ZnO ceramics was studied by using a simplified phenomenological grain growth kinetics equation Gn = K0 · t · exp(-Q/RT) together with the physical properties of sintered samples. The samples, prepared by conventional ceramics processing techniques, were sintered at temperatures between 1050 to 1250 °C for 1, 2, 3, 5 and 10 hours in air. The kinetic grain growth exponent value (n) and the activation energy for the grain growth of the 0.1 mol % B2O3-doped ZnO ceramics were found to be 2.8 and 332 kJ/mol, respectively. By increasing B2O3 content to 1 mol %, the grain growth exponent value (n) and the activation energy decreased to 2 and 238 kJ/mol, respectively. The XRD study revealed the presence of a second phase, Zn3B2O6 formed when the B2O3 content was > 1 mol %. The formation of Zn3B2O6 phase gave rise to an increase of the grain growth kinetic exponent and the grain growth activation energy. The kinetic grain growth exponent value (n) and the activation energy for the grain growth of the 2 mol % B2O3-doped ZnO ceramics were found to be 3 and 307 kJ/mol, respectively. This can be attributed to the second particle drag (pinning) mechanism in the liquid phase sintering.

Download Full-text

Grain Growth Kinetics of (NdPr)2Fe14B Magnets

Materials Science Forum ◽

10.4028/www.scientific.net/msf.802.540 ◽

2014 ◽

Vol 802 ◽

pp. 540-545 ◽

Cited By ~ 1

Author(s):

Kaio Sérgio Torres de Souza ◽

Célio de Jesus Marcelo ◽

Daniel Rodrigues ◽

José Adilson de Castro ◽

Marcos Flavio de Campos

Keyword(s):

Grain Size ◽

Grain Growth ◽

Growth Kinetics ◽

Energy Product ◽

Heat Treated ◽

Coarsening Kinetics ◽

Grain Growth Kinetics ◽

Kinetics Of

Two different effects need to be considered in the sintering: (i) The densification should be maximum, to optimize the energy product BHmax and the remanence, however, (ii) the .grain size should be small, in order to maximize the coercivity. Grain growth takes place during the sintering step of the magnets, usually performed at the range 1000-1100°C. In this study, the grain growth kinetics is investigated. Samples of NdPrFeB magnets (proportion 3 Nd : 1 Pr) were heat treated at the temperature of 1050 °C, for times between 1 to 12 hours. The knowledge of the grain growth and coarsening kinetics allows extrapolation to other temperatures, and this information is helpful to maximize coercivity and remanence at the same time.

Download Full-text