scholarly journals Isothermal omega Assisted Alpha Phase Precipitation and Microstructural Evolution of an Aged Ti-30Nb-3Fe Alloy

2020 ◽  
Vol 23 (3) ◽  
Author(s):  
Mariana G. de Mello ◽  
Fernando H. Costa ◽  
Victor Opini ◽  
Arthur Resende ◽  
Alessandra Cremasco ◽  
...  
Keyword(s):  
Microstructural Evolution ◽  
Alpha Phase ◽  
Phase Precipitation

Effect of boundary on the alpha phase precipitation in a near-alpha titanium alloy

2018 ◽  
Vol 233 ◽  
pp. 298-301 ◽  
Author(s):  
Xiongxiong Gao ◽  
Weidong Zeng ◽  
Xin Li ◽  
Dadi Zhou ◽  
Jianwei Xu ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Alpha Phase ◽  
Phase Precipitation ◽  
Alpha Titanium

scholarly journals Deformation and Phase Transformation of Disorder α Phase at (α+γ) two Phase Region in high Nb Containing TiAl alloy

2021 ◽  
Author(s):  
Haitao Zhou ◽  
Fantao Kong ◽  
Yanbo Wang ◽  
Xiangwu Hou ◽  
Ning Cui ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Microstructural Evolution ◽  
Microstructure Evolution ◽  
Tial Alloy ◽  
Temperature Drop ◽  
Alpha Phase ◽  
Phase Region ◽  
Two Phase ◽  
Α Phase ◽  
Assisted Decomposition

In this paper, the deformation and phase transformation of disorder α phase at (α + γ) two phase region in as-forged Ti-44Al-8Nb-(W, B, Y) alloy are investigated by hot compression and hot packed rolling. Detailed microstructural evolution demonstrates that the as-deformed microstructure is significantly affected by deformation conditions. The mircrostructure differences are mainly due to temperature drop and strain rate. The evolution of α lamelae into α grains is detailed descripted. Moreover, the disorder α lamellae can also be decomposed into some new α grains by the assisted decomposition mechanism of γ grains. Microstructure evolution model of current TiAl alloy at 1250 °C during hot rolling is built.

scholarly journals Microstructural evolution of h-BN matrix composite ceramics with La-Al-Si-O glass phase during hot-pressed sintering

2020 ◽  
Author(s):  
Baofu Qiu ◽  
Xiaoming Duan ◽  
Zhuo Zhang ◽  
Chen Zhao ◽  
Bo Niu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Elastic Modulus ◽  
Microstructural Evolution ◽  
Glass Phase ◽  
Sintering Temperature ◽  
Raw Materials ◽  
Sintering Process ◽  
Composite Ceramics ◽  
Phase Precipitation

Abstract BN/La-Al-Si-O composite ceramics were fabricated by hot-pressed sintering using h-BN, La2O3, Al2O3 and amorphous SiO2 as the raw materials. The effects of sintering temperature on the microstructural evolution, bulk density, apparent porosity, and mechanical properties of h-BN composite ceramics were investigated. The results indicated that La-Al-Si-O liquid phase was formed during sintering process, which provided an environment for the growth of h-BN grains. With increasing sintering temperature, the cristobalite phase precipitation and h-BN grain growth occurred at the same time, which had the significant influence on the densification and mechanical properties of h-BN composite ceramics. The best mechanical properties of BN/La-Al-Si-O composite ceramics were obtained under sintering temperature of 1700 °C, and the elastic modulus, flexural strength, and fracture toughness were 80.5 GPa, 266.4 MPa and 3.25 MPa·m1/2, respectively.

Alpha phase precipitation in delta phase plutonium

1967 ◽  
Vol 24 (2) ◽  
pp. 223-229
Author(s):  
R.A. Knight ◽  
B.R. Spicer ◽  
B.J. Ward ◽  
J.S. White
Keyword(s):  
Alpha Phase ◽  
Phase Precipitation ◽  
Delta Phase

Phase Transformation and Densification of Nanostructured Alumina. Effect of Seeding and Doping

2005 ◽  
Vol 237-240 ◽  
pp. 665-670 ◽  
Author(s):  
Corinne Legros ◽  
Claude Carry ◽  
Sylvie Lartigue-Korinek ◽  
Paul Bowen
Keyword(s):  
Phase Transformation ◽  
Microstructural Evolution ◽  
Nucleation Rate ◽  
Short Range ◽  
Alpha Phase ◽  
Densification Behaviour ◽  
Kinetics Of ◽  
Alpha Alumina

By following the densification kinetics of nanocrystalline g alumina and corresponding microstructural evolution we showed that the diffusive transformation gamma-alpha involves several processes such as nucleation of alpha phase, rearrangement of gamma crystallite at alpha seed and grain surfaces, formation of porous alpha alumina monocrystalline colonies. Results concerning the effects of seeding and doping elements on the transformation-densification behaviour of the same g-alumina raw powder batch are also presented. Doping elements seem to have no influence on nucleation rate but could modify the redistribution rate of the ions during the transformation by short range diffusion of doping elements.

Alpha phase precipitation in Ti-30Nb-1Fe alloys – phase transformations in continuous heating and aging heat treatments

2016 ◽  
Vol 677 ◽  
pp. 222-229 ◽  
Author(s):  
Fernando Henrique da Costa ◽  
Camilo A.F. Salvador ◽  
Mariana G. de Mello ◽  
Rubens Caram
Keyword(s):  
Phase Transformations ◽  
Alpha Phase ◽  
Heat Treatments ◽  
Continuous Heating ◽  
Phase Precipitation

Influence of heating rate and aging temperature on omega and alpha phase precipitation in Ti 35Nb alloy

2018 ◽  
Vol 145 ◽  
pp. 268-276 ◽  
Author(s):  
Mariana G. de Mello ◽  
Beatriz P. Dainese ◽  
Rubens Caram ◽  
Alessandra Cremasco
Keyword(s):  
Heating Rate ◽  
Aging Temperature ◽  
Alpha Phase ◽  
Phase Precipitation ◽  
35Nb Alloy

scholarly journals Microstructural Evolution of H-BN Matrix Composite Ceramics With Amorphous La2O3-Al2O3-SiO2 Glass Phase During Hot Pressing

2020 ◽  
Author(s):  
Baofu Qiu ◽  
Xiaoming Duan ◽  
Zhuo Zhang ◽  
Chen Zhao ◽  
Bo Niu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Microstructural Evolution ◽  
Glass Phase ◽  
Sintering Temperature ◽  
Raw Materials ◽  
Sintering Process ◽  
Hot Press ◽  
Composite Ceramics ◽  
Phase Precipitation ◽  
Hot Press Sintering

Abstract BN-La2O3-Al2O3-SiO2 composite ceramics were fabricated by hot press sintering using h-BN, La2O3, Al2O3 and amorphous SiO2 as the raw materials. The effects of sintering temperature on the microstructural evolution, bulk density, apparent porosity, and mechanical properties of h-BN composite ceramics were investigated. The results indicated that ternary La2O3-Al2O3-SiO2 liquid phase was formed during sintering process, which provided an environment for the growth of h-BN grains. With increasing sintering temperature, the cristobalite phase precipitation and h-BN grain growth occurred at the same time, which had the significant influence on the densification and mechanical properties of h-BN composite ceramics. The best mechanical properties of BN-La2O3-Al2O3-SiO2 composite ceramics were obtained under sintering temperature of 1700 °C, and the elastic modulus, flexural strength, and fracture toughness were 80.5 GPa, 266.4 MPa and 3.25 MPa·m1/2, respectively.

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