Degradation Mechanisms of Epoxy Molding Compound Subjected to High Temperature Long Term Aging

2021 ◽  
Author(s):  
Pradeep Lall ◽  
Yunli Zhang ◽  
Jaimal Williamson
Keyword(s):  
High Temperature ◽  
Degradation Mechanisms ◽  
Epoxy Molding Compound ◽  
Molding Compound

scholarly journals Effects of High-Temperature Storage on the Elasticity Modulus of an Epoxy Molding Compound

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 684
Author(s):  
Ruifeng Li ◽  
Daoguo Yang ◽  
Ping Zhang ◽  
Fanfan Niu ◽  
Miao Cai ◽  
...  
Keyword(s):  
High Temperature ◽  
Elasticity Modulus ◽  
Glassy State ◽  
Storage Conditions ◽  
Material Structure ◽  
Epoxy Molding Compound ◽  
Molding Compound ◽  
Different Temperatures ◽  
Temperature Storage

Changes in the elasticity modulus of an epoxy molding compound (EMC), an electronic packaging polymer, under high-temperature air storage conditions, are discussed in this study. The elasticity modulus of EMC had two different compositions (different filling contents) under different temperatures (175, 200, and 225 °C) and aging times (100, 500, and 1500 h), which were analyzed by using dynamic mechanic analysis technology. The results revealed that the elasticity modulus increased in the thermal aging process, with an increase in the temperature and the aging time. The increments of the glassy and rubbery states were similar. However, the growing rate was significantly different, and the growth of the rubbery state was significantly higher than that of the glassy state. The filling content influenced the degree of aging of the materials significantly. At a low filling content, long-term aging under high temperatures completely changed the material structure, and the mechanical properties of the polymer were reduced.

Characterization of Linear Viscoelasticity Evolution of Epoxy Molding Compound Subjected to High Temperature Long Term Aging

2021 ◽  
Author(s):  
Pradeep Lall ◽  
Yunli Zhang ◽  
Haotian Wu ◽  
Jeff Suhling ◽  
Edward Davis ◽  
...  
Keyword(s):  
High Temperature ◽  
Power Systems ◽  
Linear Viscoelasticity ◽  
Aging Effect ◽  
Epoxy Molding Compound ◽  
Molding Compound ◽  
Long Period ◽  
Different Temperatures ◽  
Safety Systems

Abstract Much of the electronics used to support power systems and enable safety systems resides underhood where operating temperatures are much higher than in traditional consumer applications. Underhood electronics may be subjected to sustained high temperature environment 150°C for long period of time during operation. However, there is insufficient information about the viscoelasticity of epoxy molding compound stored in sustained high temperature for long period of time. In this paper, two different types of epoxy molding compounds have been prepared and aged under two different temperatures: 100°C and 150°C. Multi-frequency scan dynamic mechanical analyzer (DMA) test has been conducted to study the viscoelasticity evolution from pristine, 40 days, 80 days, 120 days. The master curve has been obtained and the prony parameters of EMCs have been calculated. The aging effect of linear viscoelasticity has been discussed.

Effects of Microstructures on Strength and Fatigue Properties of Long-Term-Serviced F12 Steels

2007 ◽  
Vol 353-358 ◽  
pp. 295-298
Author(s):  
X.M. Wu ◽  
G.P. Zhang ◽  
J.Q. Zhang ◽  
W.G. Chen
Keyword(s):  
Fatigue Crack ◽  
High Temperature ◽  
Fatigue Crack Initiation ◽  
Fatigue Properties ◽  
Degradation Mechanisms ◽  
Creep Properties ◽  
Running Time ◽  
Electron Microscopes ◽  
Term Creep

Microstructures of long-term serviced F12 steel exposed at 545 °C have been investigated by electron microscopes. The hardness of the material was measured to be correlated with the variation of the microstructures. Fatigue properties of the material with different running time were evaluated and analyzed. The experimental results show that the coarsening of the precipitated carbides along boundaries and the formation of subgrains accelerate the degradation of the long-term creep properties of the steel. Fatigue crack initiation threshold from a notch linearly deceases with increasing the running time due to the variation of the distribution and the shape of the precipitated carbides. The degradation mechanisms of the F12 steel during their long-term service at high temperature are discussed.

Effects of High-Temperature Storage on the Glass Transition Temperature of Epoxy Molding Compound

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Ruifeng Li ◽  
Daoguo Yang ◽  
Ping Zhang ◽  
Fanfan Niu ◽  
Miao Cai ◽  
...  
Keyword(s):  
Glass Transition ◽  
High Temperature ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Storage Conditions ◽  
Mechanical Analysis ◽  
Core Material ◽  
Epoxy Molding Compound ◽  
Molding Compound ◽  
Different Temperatures

Abstract This article describes research on changes of glass transition temperature of electron encapsulated polymer-epoxy molding compound (EMC) after thermal oxidation under high-temperature air storage conditions. The evolutions of glass transition temperature of two EMCs with different compositions (different filling contents) under different temperatures (175, 200, and 225 °C) and different aging times (100, 500, and 1500 h) were analyzed by dynamic mechanical analysis (DMA) technology. Research results demonstrated that two glass transition temperatures occurred during thermal aging. These two temperatures were the glass transition temperature of the unaged core material (Tg1) and the glass transition temperature of completely oxidized surface material (Tg2). Tg2 increased continuously with the increase of temperature and the prolonging of the aging time. The filling content could have significantly influenced the aging degree of materials.

Microstructural characterization of a rapidly solidified Al-Fe-V-Si alloy for elevated temperature applications

1988 ◽  
Vol 46 ◽  
pp. 550-551
Author(s):  
R. E. Franck ◽  
J. A. Hawk ◽  
G. J. Shiflet
Keyword(s):  
High Temperature ◽  
Elevated Temperature ◽  
Grain Growth ◽  
Volume Fraction ◽  
Microstructural Characterization ◽  
Second Phase ◽  
Microstructural Stability ◽  
Elevated Temperature Strength ◽  
Temperature Applications

Rapid solidification processing (RSP) is one method of producing high strength aluminum alloys for elevated temperature applications. Allied-Signal, Inc. has produced an Al-12.4 Fe-1.2 V-2.3 Si (composition in wt pct) alloy which possesses good microstructural stability up to 425°C. This alloy contains a high volume fraction (37 v/o) of fine nearly spherical, α-Al12(Fe, V)3Si dispersoids. The improved elevated temperature strength and stability of this alloy is due to the slower dispersoid coarsening rate of the silicide particles. Additionally, the high v/o of second phase particles should inhibit recrystallization and grain growth, and thus reduce any loss in strength due to long term, high temperature annealing.The focus of this research is to investigate microstructural changes induced by long term, high temperature static annealing heat-treatments. Annealing treatments for up to 1000 hours were carried out on this alloy at 500°C, 550°C and 600°C. Particle coarsening and/or recrystallization and grain growth would be accelerated in these temperature regimes.

KUBOTA KNC-03

Alloy Digest ◽  
2010 ◽  
Vol 59 (1) ◽  
Keyword(s):  
Compressive Strength ◽  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
High Strength ◽  
Temperature Performance ◽  
Resistance To Oxidation

Abstract Kubota KNC-03 is a grade with a combination of high strength and excellent resistance to oxidation. These properties make this alloy suitable for long-term service at temperature up to 1250 deg C (2282 deg F). This datasheet provides information on physical properties, hardness, elasticity, tensile properties, and compressive strength as well as creep. It also includes information on high temperature performance as well as casting and joining. Filing Code: Ni-676. Producer or source: Kubota Metal Corporation, Fahramet Division. See also Alloy Digest Ni-662, April 2008.

ATI 6-2-4-2

Alloy Digest ◽  
2020 ◽  
Vol 69 (8) ◽  
Keyword(s):  
Tensile Strength ◽  
Titanium Alloy ◽  
High Temperature ◽  
Creep Strength ◽  
High Strength ◽  
Heat Treating ◽  
Good Combination ◽  
Long Term Stability ◽  
Temperature Performance

Abstract ATI 6-2-4-2 is a near-alpha, high strength, titanium alloy that exhibits a good combination of tensile strength, creep strength, toughness, and long-term stability at temperatures up to 425 °C (800 °F). Silicon up to 0.1% frequently is added to improve the creep resistance of the alloy. This datasheet provides information on composition, physical properties, hardness, and tensile properties as well as creep. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: Ti-169. Producer or Source: ATI.

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