Microstructures and Damping Capacity of Mg-6Zn-0.5Zr Alloy

2012 ◽  
Vol 557-559 ◽  
pp. 1624-1628 ◽  
Author(s):  
Xian Lan Liu ◽  
Chu Ming Liu ◽  
Wen Yu Zhang ◽  
Jian Hua Luo ◽  
Su Min Zeng
Keyword(s):  
Strain Amplitude ◽  
Critical Strain ◽  
Damping Capacity ◽  
Damping Properties ◽  
Dynamic Mechanical Analyzer ◽  
Dynamic Mechanical ◽  
Experimental Strain ◽  
Damping Peak ◽  
Peak Value

The dynamic mechanical analyzer (DMA) was applied to investigate the damping properties of Mg-6Zn-0.6Zr alloys. The results show that the as-cast Mg-6Zn-0.6Zr alloy exhibits higher strain amplitude independent damping performance than that of as-homogenized. The strain amplitude dependent damping of the as-homogenized has the best damping performance with the strain amplitude from 3×10-5 to 6×10-4, and the as-extruded is the lowest. When the strain amplitude exceeded 6×10-4, the as-extruded has the best damping capacity all the time within the experimental strain amplitude, and all the alloys reach the high damping capacity. Two critical strain amplitude points were detected in the alloy as-extruded and as-homogenized. The damping peak value is 0.0192 with the strain amplitude of 1.5×10-3 presented in the alloy as-extruded.

scholarly journals Strain Amplitude Dependence of High Damping Grp/Mg97Zn1Y2 Composites Ranging from Anelastic to Microplastic

Metals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1570
Author(s):  
Diqing Wan ◽  
Shaoyun Dong ◽  
Yinglin Hu ◽  
Jiajun Hu ◽  
Yandan Xue ◽  
...  
Keyword(s):  
Particle Size ◽  
Strain Amplitude ◽  
Graphite Particle ◽  
Weak Interactions ◽  
Damping Capacity ◽  
Amplitude Dependence ◽  
Damping Properties ◽  
Microplastic Strain ◽  
Anelastic Strain ◽  
Transmission Electron

In this paper, the damping capacities and damping mechanisms of high damping, graphite-reinforced Mg97Zn1Y2 composites were investigated. Composites consisting of different graphite particle sizes (24, 11, and 3 μm) were designed and prepared using the casting method. The microstructure of the composites was examined using optical microscopy (OM) and transmission electron microscopy (TEM), which confirmed that the graphite particles were successfully planted into the Mg97Zn1Y2 matrix. Measurements made with a dynamic mechanical analyzer (DMA) showed that the Grp/Mg97Zn1Y2 composite has a high damping capacity. At the anelastic strain amplitude stage, the damping properties of the Grp/Mg97Zn1Y2 composites were found to be higher than those of the Mg97Zn1Y2 alloy. Furthermore, decreasing the graphite particle size was found to improve the damping properties of the Grp/Mg97Zn1Y2 composites. At the microplastic strain amplitude stage, the damping properties of the Mg97Zn1Y2 alloy were found to be higher than those of the Grp/Mg97Zn1Y2 composites. Moreover, the damping properties of the Grp/Mg97Zn1Y2 composites were found to decrease with increasing graphite particle size. The reason for the increased damping of the Grp/Mg97Zn1Y2 composites during the anelastic strain amplitude stage can be attributed to the increase in the number of damping sources and weak interactions among the dislocation damping mechanisms. At the microplastic strain amplitude stage, the damping properties of the composite are mainly affected by the activation volume of the slipped dislocation.

The Effect of Nano-Filler on the Damping Properties of Polyacrylic Damping Paint

2011 ◽  
Vol 183-185 ◽  
pp. 2154-2157 ◽  
Author(s):  
Peng Chen ◽  
Yang Liu ◽  
Ming Wei Di
Keyword(s):  
Loss Factor ◽  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Damping Properties ◽  
Dynamic Mechanical ◽  
Temperature Range ◽  
Nano Silicon ◽  
Polyacrylic Ester ◽  
Peak Value ◽  
Rubber Filler

The dynamic mechanical properties of the blends of polyacrylic ester and various nano-fillers and the effect of nano-filler on the damping properties of polyacrylic ester damping paint were studied by using dynamic mechanical analysis (DMA) in this paper. The experiment results showed that the glass-transition temperature (Tg), loss factor peak value and effective damping temperature range for the polyacrylic ester damping paint changed correspondingly after blended with various nano-fillers. The damping properties and effective damping temperature range of the polyacrylic ester damping paint would be improved effectively by adding nano-polyacrylic ester rubber filler; the nano-silicon dioxide could enhance the damping properties for the polyacrylic ester damping paint, but the degree of improvement for effective damping temperature range was inferior to nano-polyacrylic ester rubber filler; and the nano-calcium carbonate could also improve the damping properties of the damping paint, but the effective damping temperature range was hardly improved.

Application of G-L Dislocation Model in Low Frequency Damping Capacities of AZ91D and SiCw/AZ91D Composites

2007 ◽  
Vol 546-549 ◽  
pp. 495-498
Author(s):  
Y.K. Zhang ◽  
Xiao Shi Hu ◽  
Kun Wu ◽  
Ming Yi Zheng
Keyword(s):  
Strain Amplitude ◽  
High Strain ◽  
Low Frequency ◽  
Small Strain ◽  
Damping Capacity ◽  
Dislocation Model ◽  
Az91d Alloy ◽  
Dynamic Mechanical Analyzer ◽  
Squeeze Cast ◽  
Strong Pinning

The low frequency damping capacities of commercial cast AZ91D, squeeze cast AZ91D alloy and SiCw/AZ91D composite were studied using dynamic mechanical analyzer (DMA). The obtained strain amplitude dependent damping could be divided into two regions. In the region of small strain amplitude, the damping capacity was independent of the amplitude. While at high strain region, the damping capacity increased rapidly with increasing of strain amplitude. The G-L dislocation model was used to explain the damping capacity, and the differences of the distance between the weak and strong pinning points were discussed. The microstructures of the alloys and composites were observed and coincided with the analysis results according to G-L dislocation model.

Different Damping Dependences on Volume Fractions of Thermal and Deformation-Induced ε Martensites in an Fe-Mn Alloy

2006 ◽  
Vol 319 ◽  
pp. 79-84 ◽  
Author(s):  
Joong Hwan Jun ◽  
Young Kook Lee ◽  
Jeong Min Kim ◽  
Ki Tae Kim ◽  
Woon Jae Jung
Keyword(s):  
Cold Rolling ◽  
Electron Micrographs ◽  
Damping Capacity ◽  
Damping Properties ◽  
Number Density ◽  
Volume Fractions ◽  
Martensite Content ◽  
Transmission Electron ◽  
Ε Martensite ◽  
Peak Value

We reports the damping properties of an Fe-23%Mn alloy with various amounts of thermal or deformation-induced ε martensite. By controlling cooling temperatures and cold rolling degrees, the volume fractions of thermal and deformation-induced ε martensites are changed from 33 to 50% and from 33 to 75%, respectively. The damping capacity of the Fe-23%Mn alloy increases with an increase in thermal ε martensite content, whereas the damping capacity associated with deformation-induced ε martensite shows a peak value at 57% of ε martensite. Transmission electron micrographs on deformed samples reveal that the decay of damping over 57% of deformation-induced ε martensite is caused by an introduction of perfect dislocations, which play a role in suppressing the movement of damping sources. For the same amount of ε martensite, deformation-induced ε martensite exhibits higher level of damping capacity than thermal ε martensite. This may well be owing to relatively greater length of γ/ε interfaces in response to higher number density of ε martensite plates.

scholarly journals Multiscale Characterization of E-Glass/Epoxy Composite Exposed to Extreme Environmental Conditions

2021 ◽  
Vol 5 (3) ◽  
pp. 80
Author(s):  
George Youssef ◽  
Scott Newacheck ◽  
Nha Uyen Huynh ◽  
Carlos Gamez
Keyword(s):  
Power Distribution ◽  
Epoxy Composite ◽  
Fire Retardant ◽  
Sandwich Composite ◽  
Dynamic Mechanical Analyzer ◽  
Fire Event ◽  
Balsa Wood ◽  
X Ray ◽  
Dynamic Mechanical ◽  
Composite Skins

Fiber-reinforced polymer matrix composites continue to attract scientific and industrial interest since they offer superior strength-, stiffness-, and toughness-to-weight ratios. The research herein characterizes two sets of E-Glass/Epoxy composite skins: stressed and unstressed. The stressed samples were previously installed in an underground power distribution vault and were exposed to fire while the unstressed composite skins were newly fabricated and never-deployed samples. The mechanical, morphological, and elemental composition of the samples were methodically studied using a dynamic mechanical analyzer, a scanning electron microscope (SEM), and an x-ray diffractometer, respectively. Sandwich composite panels consisting of E-glass/Epoxy skin and balsa wood core were originally received, and the balsa wood was removed before any further investigations. Skin-only specimens with dimensions of ~12.5 mm wide, ~70 mm long, and ~6 mm thick were tested in a Dynamic Mechanical Analyzer in a dual-cantilever beam configuration at 5 Hz and 10 Hz from room temperature to 210 °C. Micrographic analysis using the SEM indicated a slight change in morphology due to the fire event but confirmed the effectiveness of the fire-retardant agents in quickly suppressing the fire. Accompanying Fourier transform infrared and energy dispersive X-ray spectroscopy studies corroborated the mechanical and morphological results. Finally, X-ray diffraction showed that the fire event consumed the surface level fire-retardant and the structural attributes of the E-Glass/Epoxy remained mainly intact. The results suggest the panels can continue field deployment, even after short fire incident.

Dynamic Strain Effects in Elastomers

1963 ◽  
Vol 36 (2) ◽  
pp. 407-421 ◽  
Author(s):  
Glenn E. Warnaka
Keyword(s):  
Elastic Modulus ◽  
Mechanical Behavior ◽  
Strain Amplitude ◽  
Loss Factor ◽  
Dynamic Strain ◽  
Dynamic Mechanical ◽  
Small Strains ◽  
Dynamic Mechanical Behavior ◽  
Elastomeric Materials ◽  
Practical Engineering

Abstract Many common elastomeric materials have two ranges of dynamic-mechanical behavior. Such materials behave as viscoelastomers at very small strains and as plastoelastomers at strains of practical engineering interest. The change from viscoelastic to plastoelastic behavior occurs at dynamic strain amplitudes of 0.001 inches per inch to 0.005 inches per inch. In the plastoelastic range, the dynamic elastic modulus decreases with increasing dynamic strain amplitude. Loss factor reaches a maximum in the plastoelastic range.

scholarly journals THE INFLUENCE OF SEVERAL TYPES OF RESINS ON THE DYNAMIC MECHANICAL PROPERTIES OF POLYMER MIXTURE BASED ON BUTYL RUBBER

2020 ◽  
Vol 3 (2) ◽  
pp. 36-45 ◽  
Author(s):  
O. Tarasova ◽  
Yu. Yurkin ◽  
A. Toroschin
Keyword(s):  
Phenol Formaldehyde ◽  
Dynamic Properties ◽  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Strength Properties ◽  
Butyl Rubber ◽  
Polymer Materials ◽  
Polymer Mixture ◽  
Damping Properties ◽  
Dynamic Mechanical

this work is devoted to the problem of developing vibration-damping polymer materials with high damping properties in a wide temperature range. The study of the effect of modifying additives on the strength, damping, adhesive and cohesive properties of a butyl rubber composite is the aim of this work. The task is to identify the actual temperature, frequency, dynamic and mechanical characteristics of a composite material based on butyl rubber depending on the type and concentration of resins. The key methods for studying this problem is the dynamic mechanical analysis method, aimed at obtaining information about changes in the dynamic properties of polymer materials (bond strength with metal when peeling samples of composites, determining the flow resistance of samples, determining the migration of plasticizer). Due to the established experimental dependences, it was found that the addition of resins (3% by weight) in the composition based on butyl rubber leads to an increase in the damping properties of composite materials, and an increase to (4.25% by weight) leads to their decrease. It was established that the obtained filled mixtures with a high damping peak and good adhesive and strength properties are mixtures with the addition of alkyl phenol-formaldehyde resins.

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