scholarly journals Thermal Aging Study of a Dow Corning SE 1700 Porous Structure Made by Direct Ink Writing: 1-Year Results and Long-Term Predictions

2015 ◽  
Author(s):  
Ward Small ◽  
Mark A. Pearson ◽  
Amitesh Maiti ◽  
Thomas R. Metz ◽  
Eric B. Duoss ◽  
...  
Keyword(s):  
Porous Structure ◽  
Thermal Aging ◽  
Direct Ink Writing ◽  
Aging Study

Effects of substrate metallizations on solder/underbump metallization interfacial reactions in flip-chip packages during thermal aging

2003 ◽  
Vol 18 (6) ◽  
pp. 1333-1341 ◽  
Author(s):  
F. Zhang ◽  
M. Li ◽  
C. C. Chum ◽  
C-H. Tung
Keyword(s):  
Porous Structure ◽  
Thermal Aging ◽  
Flip Chip ◽  
Interfacial Reactions ◽  
Snagcu Solder ◽  
Solution Type ◽  
Snpb Solder ◽  
Underbump Metallization ◽  
Eutectic Snpb

Effects of Ni and Au from Ni/Au substrate metallizations on the interfacial reactions of solder joints in flip-chip packages during long-term thermal aging were systematically investigated. It was found that both Au and Ni influenced the solid-state interfacial reactions, underbump metallization (UBM), and intermetallic compound (IMC) evolution. Because large amounts of Ni could incorporate into IMC to form a multicomponent (Cu, Ni)6Sn5 phase during assembly reflow, while Au could only affect the reaction during thermal aging through the reconfiguration of AuSn4 phase, Ni had stronger effects on solid-solution type Ni–V UBM consumption than Au. It was found that the UBM consumption process was faster in the eutectic SnPb solder system than that in the SnAgCu solder system during aging. A porous structure was formed in the UBM layer after Ni in UBM was consumed. Electrical resistance of flip-chip packages increased significantly after the porous structure reached certain extents. The results showed that the diffusion process of Ni from UBM and Sn from solder in the presence of (Cu, Ni)6Sn5 or (Ni, Cu)3Sn4 phase at solder joint interfaces could be much faster than that in the case of binary Cu6Sn5 or Ni3Sn4 IMC.

Mechanical Properties of Epoxy Adhesive Under Thermal Aging and Their Chemical Degradation Behavior

2021 ◽  
Vol 21 (8) ◽  
pp. 4444-4449
Author(s):  
Bongjin Chung ◽  
Shin Sungchul ◽  
Jaeho Shim ◽  
Seongwoo Ryu
Keyword(s):  
Mechanical Properties ◽  
Thermal Aging ◽  
Photoelectron Spectroscopy ◽  
Thermal Exposure ◽  
Chain Scission ◽  
Epoxy Adhesive ◽  
Chemical Degradation ◽  
Adhesive Properties ◽  
Noticeable Reduction

Epoxy adhesive was analyzed under long term thermal aging and mechanical properties and chemical degradation were observed by X-ray photoelectron spectroscopy (XPS). Long term thermal exposure of epoxy causes a noticeable reduction in adhesive properties. We developed a predictive model of temperature and time dependent aging. The temperature dependent aging behavior of epoxy adhesive shows good agreement with conventional Arrhenius equations. Using XPS analysis, we also discovered a correlation between chemical degradation and the adhesive properties. Decay of C–C bonding ratio induced chain-scission of epoxy adhesive; increase of total numbers of C–O and C═O induced oxidation of epoxy adhesive during thermal exposure.

Benzodiazepine long-term use among the elderly and cerebral atrophy: Results from the Vienna-transdanube-aging study, ”VITA“

2002 ◽  
Vol 12 ◽  
pp. 364
Author(s):  
C. Barnas ◽  
E. Hilger ◽  
W. Krampla ◽  
S. Jungwirth ◽  
P. Fischer ◽  
...  
Keyword(s):  
Cerebral Atrophy ◽  
The Elderly ◽  
Aging Study

Fracture Toughness of Z3CN20.09M Cast Stainless Steel with Long-Term Thermal Aging

2017 ◽  
Vol 26 (9) ◽  
pp. 4442-4449 ◽  
Author(s):  
Weiwei Yu ◽  
Dunji Yu ◽  
Hongbo Gao ◽  
Fei Xue ◽  
Xu Chen
Keyword(s):  
Fracture Toughness ◽  
Stainless Steel ◽  
Thermal Aging ◽  
Cast Stainless Steel

scholarly journals Do Stress Trajectories Predict Mortality in Older Men? Longitudinal Findings from the VA Normative Aging Study

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Carolyn M. Aldwin ◽  
Nuoo-Ting Molitor ◽  
Avron Spiro ◽  
Michael R. Levenson ◽  
John Molitor ◽  
...  
Keyword(s):  
Allostatic Load ◽  
Stressful Life Events ◽  
High Stress ◽  
Theoretical Models ◽  
Growth Mixture Model ◽  
Growth Mixture ◽  
Aging Study ◽  
Health Related ◽  
The Relationship

We examined long-term patterns of stressful life events (SLE) and their impact on mortality contrasting two theoretical models: allostatic load (linear relationship) and hormesis (inverted U relationship) in 1443 NAS men (aged 41–87 in 1985;M= 60.30, SD = 7.3) with at least two reports of SLEs over 18 years (total observations = 7,634). Using a zero-inflated Poisson growth mixture model, we identified four patterns of SLE trajectories, three showing linear decreases over time with low, medium, and high intercepts, respectively, and one an inverted U, peaking at age 70. Repeating the analysis omitting two health-related SLEs yielded only the first three linear patterns. Compared to the low-stress group, both the moderate and the high-stress groups showed excess mortality, controlling for demographics and health behavior habits, HRs = 1.42 and 1.37,ps<.01and<.05. The relationship between stress trajectories and mortality was complex and not easily explained by either theoretical model.

Evolution and its stability of M23(C,N)6 carbonitride in martensite ferritic steel during long-term thermal aging

2019 ◽  
Vol 152 ◽  
pp. 36-43 ◽  
Author(s):  
Zixi Wang ◽  
Hongchang Zhao ◽  
Lei Chen ◽  
Guorui Wu ◽  
Yan Wang ◽  
...  
Keyword(s):  
Thermal Aging ◽  
Ferritic Steel
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