scholarly journals Experimental investigation on the effect of platform heating on the dynamic mechanical properties of selective laser manufacturing of AlSi10Mg alloy

2021 ◽  
Vol 250 ◽  
pp. 05016
Author(s):  
Ben Amir ◽  
Eyal Grinberg ◽  
Yuval Gale ◽  
Oren Sadot ◽  
Shmuel Samuha
Keyword(s):  
Mechanical Properties ◽  
Three Dimensional ◽  
Stress Relief ◽  
Dynamic Mechanical Properties ◽  
Layer By Layer ◽  
Dynamic Mechanical ◽  
Machine Manufacturer ◽  
Laser Manufacturing ◽  
Lightweight Alloys ◽  
The Difference

Additive manufacturing (AM) is one of the emerging promising technology technologies of manufacturing prototypes. The process of AM is based on melting powder by an energetic beam layer by layer to create a three-dimensional body. One of the lightweight alloys that is being used for AM is AlSi10Mg. The process of manufacturing is controlled by several tens of parameters most of which are determined by the machine manufacturer. One of the important parameters is the building platform temperature. In the present study we took samples from different heights of the building platform and measured the dynamic mechanical properties of each sample. It was noted that after a stress relief treatment (SRT) the difference in the static and dynamic mechanical properties along the building direction changed differently. The dynamic mechanical properties of samples that were fabricated in proximity to the building platform did not change after the SRT, while the mechanical properties of the samples that were fabricated far from the platform changed dramatically and became like those that were fabricated near the building plate.

Dynamic Mechanical Properties of MWNTs/Phenolic Nanocomposites

2006 ◽  
Vol 306-308 ◽  
pp. 1073-1078 ◽  
Author(s):  
Meng Kao Yeh ◽  
Nyan Hwa Tai ◽  
Jia Hau Liu
Keyword(s):  
Mechanical Properties ◽  
Transition Temperature ◽  
Phenolic Resin ◽  
Loss Modulus ◽  
Impact Resistance ◽  
Dynamic Mechanical Properties ◽  
Tensile Failure ◽  
Dynamic Mechanical ◽  
Multi Walled Carbon Nanotube ◽  
The Difference

Two different types of multi-walled carbon nanotube (MWNT), the dispersed and the network MWNTs, were used to reinforce the phenolic resin. The MWNTs/phenolic nanocomposites were tested by a dynamic mechanical analyzer (DMA) to characterize their dynamic mechanical properties. The results showed that increasing the MWNT content can increase the storage modulus, the loss modulus and the glassy transition temperature of the MWNTs/phenolic nanocomposites. A subambient loss transition is seen in the nanocomposites with network MWNTs which results in a better impact resistance property in the nanocomposites. The glassy transition temperature of the nanocomposites with network MWNTs is higher than that of nanocomposites with dispersed MWNTs. The MWNT additive in phenolic resin can be used to improve the dynamic mechanical properties of the MWNTs/phenolic nanocomposites. The tensile failure morphologies of MWNTs/phenolic nanocomposites were also examined using field emission scanning electron microscope (FESEM) to explain the difference between the two types of nanocomposites.

Dynamic Mechanical Analysis of ABS From Hybrid Additive Manufacturing by Fused Filament Fabrication and Shot Peening

2020 ◽  
Author(s):  
Haitham Hadidi ◽  
Brady Mailand ◽  
Tayler Sundermann ◽  
Ethan Johnson ◽  
Rakeshkumar Karunakaran ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Dynamic Mechanical Analysis ◽  
Shot Peening ◽  
Extrusion Process ◽  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Layer By Layer ◽  
Fused Filament Fabrication ◽  
Dynamic Mechanical

Abstract The mechanical properties of 3D printed polymers parts are process parameter dependent. Defects such as inadvertent voids between deposited rasters and layers lead to weakness in produced parts, which results in inferior mechanical properties as compared to injection molding. An alternative method to change energy absorption and stiffness of a polymer is hybrid additive manufacturing (AM). Hybrid-AM is the use of additive manufacturing with one or more secondary processes that are fully coupled and synergistically affect part quality, functionality, and/or process performance. In this study, fused filament fabrication (FFF) was coupled with layer-by-layer shot peening to study the dynamic mechanical properties of ABS 430 polymer using dynamic mechanical analysis (DMA). FFF is a heated extrusion process. Shot peening is a mechanical surface treatment that impinges a target with a stochastically dispersed, high velocity stream of beads. Compressive residual stress was imparted to preferential layer intervals during printing to modify the elasticity (stiffness), viscosity, toughness, and glass transition temperature. Viscoelastic and dynamic mechanical properties are important to the performance of polymers in automotive, aerospace, electronics, and medical components. Coupling printing and peening increased the storage and loss moduli as well as the tangent delta. DMA results suggest that preferential layer sequences exist that possess higher elasticity and better absorb energy upon sinusoidal dynamic loading.

scholarly journals Dynamic Mechanical Properties and Visco-Elastic Damage Constitutive Model of Freeze–Thawed Concrete

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4056 ◽  
Author(s):  
Yan Li ◽  
Yue Zhai ◽  
Wenbiao Liang ◽  
Yubai Li ◽  
Qi Dong ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Damage Evolution ◽  
Dynamic Mechanical Properties ◽  
Freeze Thaw ◽  
Dynamic Mechanical ◽  
Damage Constitutive Model ◽  
Concrete Materials ◽  
The Difference ◽  
Stress Damage ◽  
Elastic Damage

To study the dynamic mechanical characteristics and constitutive relation of concrete materials under freeze–thaw (FT) cycle conditions, C35 concrete was taken as the research object in this paper, and FT tests were carried out with a freeze–thaw range of −20–20 °C and a freeze–thaw frequency up to 50 times. By using the separated Hopkinson pressure bar (SHPB) system, impact compression tests of concrete specimens under different FT cycle actions were developed, then the dynamic fracture morphology, fracture block distribution, stress–strain curve, peak stress and other dynamic mechanical properties of concrete were analyzed, and the influence law of FT action and strain rate was obtained. Through introducing the freeze–thaw deterioration damage factor and the stress damage variable, the dynamic visco-elastic damage constitutive equation of freeze–thawed concrete was constructed based on component combination theory. Furthermore, the damage evolution process and mechanism of freeze–thawed concrete materials were revealed. The research results show that the dynamic mechanical properties of concrete under a freeze–thaw environment are the combined results of the freeze–thaw deterioration effect and the strain rate strengthening effect. The dynamic visco-elastic damage constitutive model established in this paper can effectively describe the dynamic mechanical properties of freeze–thawed concrete, and has the characteristics of few parameters and good effect. The stress damage evolution path of concrete goes backward with the increase of FT cycles and the development speed gradually slows down. The greater the difference in FT cycles, the greater the difference in stress damage path.

Polyurethanes based on hydroxylated rapeseed oil: thermal and dynamic mechanical properties

2015 ◽  
Vol 37 (2) ◽  
pp. 162-167
Author(s):  
V.A. Vilensky ◽  
◽  
L.V. Kobrina ◽  
S.V. Riabov ◽  
Y.Y. Kercha ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Rapeseed Oil ◽  
Dynamic Mechanical Properties ◽  
Dynamic Mechanical
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