Evolution of the microstructure and mechanical properties of additively manufactured AlSi10Mg during room temperature holds and low temperature aging

2020 ◽  
Vol 36 ◽  
pp. 101429 ◽  
Author(s):  
John Fite ◽  
Suhas Eswarappa Prameela ◽  
John A. Slotwinski ◽  
Timothy P. Weihs
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Room Temperature ◽  
Microstructure And Mechanical Properties ◽  
Low Temperature Aging ◽  
Temperature Aging

CAD/CAM Zirconia for Dental Application

2013 ◽  
Vol 320 ◽  
pp. 505-511
Author(s):  
Ning Li ◽  
Zhi Kai Wu ◽  
Chao Jian ◽  
Wan Qian Zhao ◽  
Jia Zhen Yan
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Key Words ◽  
20Th Century ◽  
Dental Materials ◽  
Tetragonal Zirconia ◽  
Dental Application ◽  
Cad Cam ◽  
Low Temperature Aging ◽  
Temperature Aging

During the 20th century, both dental materials and dental technologies for the fabrication of dental prosthesis progressed remarkably. Owing to the increased demand of safety and aesthetics, 3 mol% yttria stabilized tetragonal zirconia polycrystalline has been recently introduced in prosthetic dentistry for the fabrication of crowns and fixed partial dentures, in combination with CAD/CAM technique. This greatly changed the conventional dental laboratory work which is labor-intensive and experience-dependent. This review mainly introduced the state of dental zirconia and the application of CAD/CAM technology in dentistry. Key words: Dental Zirconia; CAD/CAM Technique; Mechanical Properties; Transformation Toughing; Low Temperature Aging;

Mechanical properties and low-temperature aging of tetragonal zirconia polycrystals processed by hot isostatic pressing

2003 ◽  
Vol 18 (10) ◽  
pp. 2415-2426 ◽  
Author(s):  
J. Muñoz-Saldaña ◽  
H. Balmori-Ramírez ◽  
D. Jaramillo-Vigueras ◽  
T. Iga ◽  
G. A. Schneider
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Low Temperature ◽  
Hot Isostatic Pressing ◽  
Tetragonal Zirconia ◽  
Hot Water ◽  
Full Density ◽  
Isostatic Pressing ◽  
Low Temperature Aging ◽  
Temperature Aging

The influence of grain size and density of yttria-tetragonal zirconia polycrystals (Y-TZPs) ceramics on mechanical properties and on low-temperature aging degradation (LTD) in air and in hot water was investigated. A TZP powder containing 3 mol% Y2O3 was consolidated by slip casting and densified by the sintering/hot isostatic pressing (HIP) method. Only the presintered samples that contained less than 0.15% open porosity reached near full density after HIP. The best conditions to reach full density were found to be attained by presintering and HIP both at 1400 °C. At these conditions, some of the best mechanical properties such as modulus of rupture and Weibull modulus reached 1397 ± 153 MPa and, 10.6, respectively. These values were clearly higher than those obtained from sintered bodies and samples hot isostatically pressed at 1600 °C. Aging degradation of 3Y-TZP materials can be avoided through microstructural design. Fully dense materials with a critical grain size <0.36 μm did not show any evidence of degradation after extreme aging conditions at pressurized autoclaving in hot water at 100, 200, and 260 °C for 8 h. We propose a criterion to predict degradation in air as well as in hot water for the characterized materials based on the microstructure and density control of the samples.

scholarly journals Influence of Isothermal ω Transitional Phase-Assisted Phase Transition From β to α on Room-Temperature Mechanical Performance of a Meta-Stable β Titanium Alloy Ti−10Mo−6Zr−4Sn−3Nb (Ti-B12) for Medical Application

2021 ◽  
Vol 8 ◽  
Author(s):  
Jun Cheng ◽  
Jinshan Li ◽  
Sen Yu ◽  
Zhaoxin Du ◽  
Xiaoyong Zhang ◽  
...  
Keyword(s):  
Phase Transition ◽  
Low Temperature ◽  
Room Temperature ◽  
Mechanical Performance ◽  
Secondary Phase ◽  
Electron Backscattered Diffraction ◽  
Low Temperature Aging ◽  
Osa Treatment ◽  
Transitional Phase ◽  
Temperature Aging

The microstructural evolution and tensile performance of a meta-stable β-type biomedical Ti−10Mo−6Zr−4Sn−3Nb (Ti-B12) alloy subjected to one-stage aging (OSA) and two-stage aging (TSA) are investigated in this work. The OSA treatment is performed at 510°C for 8 h. The TSA treatments are composed of low-temperature aging and high-temperature aging. In the first step, low-temperature aging is conducted at 325°C for 2 h. In the second step, the aging temperature is the same as that in the OSA. The result of the microstructure evolution shows that the precipitated secondary phase after aging is mainly influenced by the process of phase transition. There is a marked difference in the microstructure of the Ti-B12 alloy subjected to the OSA and TSA treatments. The needle-shaped α phases are precipitated in the parent β phase after the OSA treatment. Conversely, the short shuttle-like α phases precipitated after the TSA treatment are formed in the β matrix with the aid of the role of the isothermal ω transitional phase-assisted phase transition. The electron backscattered diffraction results indicate that the crystallographic orientation relationship of the α phases precipitated during the TSA treatment is basically analogous to those in the OSA treatment. The relatively higher tensile strength of 1,275 MPa is achieved by strengthening the effect of the short shuttle-like α precipitation with a size of 0.123 μm in length during the TSA treatment, associating with a suitable elongation of 12% at room temperature simultaneously. The fracture surfaces of the samples after the OSA and TSA treatments indicate that preventing the coarsening of the α layers in the grain boundaries is favorable for the enhancement of strength of Ti-B12 at room temperature. MTT test was carried out to evaluate the acute cytotoxicity and biocompatibility of the implanted material using L929 cells. The relative proliferation rates of cytotoxicity levels 0, 1, 2, 3, and 4 are ≥100, 80–99, 50–79, 30–49, and 0–29%, respectively. The cytotoxicity of the Ti-B12 alloy is slightly better than that of the Ti−6Al−4V alloy, which can meet the requirements of medical materials for biomedical materials.

Compendium of alloy phases observed after low temperature aging of Ni-rich NiAl

1990 ◽  
Vol 48 (4) ◽  
pp. 944-945
Author(s):  
Ivan E. Locci ◽  
P. S. Khadkikar ◽  
R. D. Noebe ◽  
K. Vedula
Keyword(s):  
Low Temperature ◽  
Room Temperature ◽  
Single Phase ◽  
Tensile Ductility ◽  
Intermetallic Alloys ◽  
Directionally Solidified ◽  
Two Phase ◽  
Low Temperature Aging ◽  
Temperature Aging ◽  
Stable And Metastable Phases

An overwhelming amount of research has been performed on Ni3Al (γ’) and NiAl (β) intermetallic alloys over the last decade. Yet, very little is known about the two phase field between these ordered compounds, including the occurrence and stability of phases other than γ’ or β Identifying and understanding these other phases are important since one approach to improving the ductility and toughness of NiAl is to design an alloy with a dual phase microstructure (i.e. NiAl + Ni3Al). Preliminary alloying attempts have encountered varying degrees of success. They range from powder metallurgy alloys with significantly increased fracture strengths over single phase (β-alloys to directionally solidified γ’ + β crystals which exhibit up to 9% tensile ductility at room temperature. Unfortunately, aging of these alloys at low temperature (<973 K) results in the formation of several complex, stable and metastable phases which may negate any original improvements in mechanical behavior.

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