scholarly journals Investigation of Additively Manufactured PEEK Modified With Glass Microballons as a Function of Density and Volume Fraction

2021 ◽  
Author(s):  
Sagar Mahalingappa Baligidad ◽  
Chethan Kumar Gangadhara ◽  
Maharudresh Aralikatte Chandrashekhar
Keyword(s):  
Thermal Stability ◽  
Strain Rate ◽  
Volume Fraction ◽  
Syntactic Foam ◽  
Rate Sensitivity ◽  
Inert Atmosphere ◽  
Strength Properties ◽  
Polymer Chains ◽  
Sensitivity Factor ◽  
Thermal Stability Of

Abstract Low density and strong mechanical characteristics make hollow glass microballons (HGM) filled polyehteretherketone (PEEK) composites excellent for aerospace, transportation and civil applications. In this study, PEEK was filled with different densities of HGMs (low, medium, and high) and varied volume fractions (Vf) of HGMs (10%, 15%, and 20%) and exposed to different strain rates to investigate thermal, physical, energy absorption, and other physico-mechanical responses. PEEK/HGMs composites demonstrated a substantial strain rate impact, with the strain rate sensitivity factor increasing as the strain rate increased while decreasing as the filler Vf increased. The density of the composites was also shown to be inversely related to their strength properties. Incorporating high-density HGMs into the PEEK resulted in the lowest composite density so far reported while ensuring mechanical properties. Scanning electron microscopy images revealed that the HGM dispersion is uniform inside the matrix. Thermal stability of the syntactic foam was investigated by using Thermo Gravity Analysis (TGA) under inert atmosphere and oxidative environment conditions. The infusion of microspheres enhances the thermal stability of LDPEs, MDPEs, and HDPEs samples in an inert environment, with HDPEs samples being the most thermally stable. This might lead to the formation of a strong bond between polymer chains and HGM particles.

A Microscopic Study on Local Strain Rate Sensitivity of Polypropylene Syntactic Foam with Microballoons

2010 ◽  
Vol 160-162 ◽  
pp. 1280-1284
Author(s):  
En Yang Wang ◽  
Masaki Omiya
Keyword(s):  
Strain Rate ◽  
Microscopic Study ◽  
Strain Rate Sensitivity ◽  
Syntactic Foam ◽  
Rate Sensitivity ◽  
Local Strain ◽  
Local Strain Rate

A Microscopic Study on Local Strain Rate Sensitivity of Polypropylene Syntactic Foam with Microballoons

Effects of Mn and Zr Addition in 6000 Series Aluminum Alloys on the Formation of Stabilized Substructures during Hot Deformation

2016 ◽  
Vol 877 ◽  
pp. 281-289 ◽  
Author(s):  
Hiroki Tanaka ◽  
Yasunori Nagai
Keyword(s):  
Heat Treatment ◽  
Thermal Stability ◽  
Aluminum Alloys ◽  
Strain Rate ◽  
Hot Deformation ◽  
Fibrous Structure ◽  
Deformation Parameters ◽  
Zr Addition ◽  
Plane Strain Compression Test ◽  
Thermal Stability Of

Thermal stability of substructures in 6000 series aluminum alloys containing Mn and Zr elements was investigated using plane-strain compression test. In order to form thermally stabilized substructures, the deformation parameters should be selected so as to correlate with kinetic precipitation during the deformation. For substructures of the alloys containing Mn and Zr elements, the substructures were stable during the heat treatment at 540 ̊C when the alloys were deformed at a temperature above 350 ̊C. The sheets rolled above 350 ̊C at a strain rate of under 3 s-1 per pass showed the fibrous structure and well developed β-fiber textures after the heat treatment at 540 ̊C. The sheets with the fibrous structure had an average Lankford value larger than one.

Strain-Rate Relationship of Aluminum Matrix Composites Predicted by Johnson-Cook Model

2011 ◽  
Vol 704-705 ◽  
pp. 935-940
Author(s):  
De Zhi Zhu ◽  
Wei Ping Chen ◽  
Yuan Yuan Li
Keyword(s):  
Strain Rate ◽  
Volume Fraction ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Compression ◽  
Aluminum Matrix ◽  
Rate Sensitivity ◽  
Aluminum Matrix Composites ◽  
Matrix Composites ◽  
Hopkinson Pressure Bar ◽  
Cook Model

Strain-rate sensitivities of 55-65vol.% aluminum 2024-T6/TiB2composites and the corresponding aluminum 2024-T6 matrix were investigated using split Hopkinson pressure bar. Results showed that 55-65vol.% aluminum 2024-T6/TiB2composites exhibited significant strain-rate sensitivities, which were three times higher than that of the aluminum 2024-T6 matrix. The strain-rate sensitivity of the aluminum 2024-T6 matrix composites rose obviously with reinforcement content increasing (up to 60%), which agreed with the previous researches. The aluminum 2024-T6/TiB2composites showed hybrid fracture characteristics including particle cracking and aluminum alloy softening under dynamic loading. The flow stresses predicted by Johnson-Cook model increased slowly when the reinforcement volume fraction ranged in 10%-40%. While the reinforcement volume fraction was over 40%, the flow stresses of aluminum matrix composites increased obviously and the strains dropped sharply. Keywords: Composite materials; Dynamic compression; Stress-strain relationship

Thermal Aging Analysis of Rubber Used for Fabric Expansion Joints

2013 ◽  
Vol 807-809 ◽  
pp. 2718-2721
Author(s):  
Li Na Ma ◽  
Yu Zeng Zhao ◽  
Hong Hua Ge ◽  
Kuai Ying Liu
Keyword(s):  
Thermal Stability ◽  
Thermal Aging ◽  
Inert Atmosphere ◽  
Expansion Joints ◽  
Chemical Structures ◽  
Before And After ◽  
The Difference ◽  
Ethylene Propylene Diene Terpolymer ◽  
Thermal Stability Of ◽  
Accelerated Thermal Aging

Several kinds of rubbers used for fabric expansion joints were studied by Thermogravimetric analysis under inert atmosphere before and after artificial accelerated thermal aging. The results showed that because of the difference of the chemical structures, the rubber aging is different. And the thermal stability of Polytetrafluoroethylene (PTFE) was obviously higher than that of other two kinds of rubbers, ethylene-propylene-diene-terpolymer rubber (EPDM) and fluororubber.

The Effect of Controlled Melt-Solidification on the Strain Rate Sensitivity of a Squeeze-Cast Hybrid-Reinforced Aluminum AA 6061 Matrix Composite

2015 ◽  
Vol 16 ◽  
pp. 1-16
Author(s):  
B.O. Malomo ◽  
O.O. Fadodun ◽  
K.M. Oluwasegun ◽  
A.T. Ogunbodede ◽  
S.A. Ibitoye ◽  
...  
Keyword(s):  
Strain Rate ◽  
Strain Rate Sensitivity ◽  
Matrix Composite ◽  
Deformation Behavior ◽  
Squeeze Casting ◽  
Volume Fraction ◽  
Tensile Elongation ◽  
Testing Machine ◽  
Rate Sensitivity ◽  
Cooling Rates

A framework based on the relationship between variations in cooling rates and volume fraction of reinforcements during solidification processing to enhance the deformation behavior of aluminum alloy AA6061 matrix composite produced with a hybrid system of reinforcements is investigated in this study. The aluminum matrix composite with 5 %, 10 % and 20 % volume fraction of reinforcements (Al2O3-SiC) was synthesized by infiltrating molten aluminum AA 6061 at a pouring temperature of 740 °C into prefabricated preforms of reinforcements at a pressure of 80 MPa, die preheat temperature of 300 °C and pressure holding time of 15 s using the squeeze casting method. By employing water jet spraying at the rate of 0.1, 0.2 and 0.3 kg/s and taking measurements using a K-type thermocouple, cooling rates were obtained in correspondence with varying volume fractions of reinforcements. The developed composites were sectioned and microstructural features were examined by optical microscopy. Tensile testing was conducted according to ASTM B557 standard using an MTS testing machine. It was observed that cooling rates decreased as the volume fraction of reinforcements was increased and the cooling time also increased accordingly during this process. With respect to deformation behavior, higher cooling rates are associated with an improvement in mechanical properties at 5 % and 10 % additions of hybrid reinforcement particles but this effect diminishes as the volume fraction of reinforcements was increased to 20 %. Also, the strain rate sensitivity (SRS) exponent increased considerably with strain rates and volume fraction of reinforcements, but the tensile elongation values decreased with increasing volume fraction of reinforcements; and the variations in these properties were most significant for samples containing 20% volume fraction of hybrid reinforcements.From the foregoing, it follows that an experimentally-determined optimal solidification range is critical to the enhancement of deformation parameters as the volume fraction of reinforcements is varied in a squeeze casting process.

Enhanced Thermal Stability and Mechanical Properties of Ultrafine-Grained Aluminum Alloy

2010 ◽  
Vol 667-669 ◽  
pp. 331-336 ◽  
Author(s):  
Rinat K. Islamgaliev ◽  
Marina A. Nikitina ◽  
Aidar F. Kamalov
Keyword(s):  
Thermal Stability ◽  
Aluminum Alloy ◽  
Volume Fraction ◽  
High Pressure Torsion ◽  
Coarse Grained ◽  
Dynamic Precipitation ◽  
Ultrafine Grained ◽  
The Mean ◽  
Fatigue Endurance ◽  
Thermal Stability Of

The paper reports on microstructure, strength and fatigue of ultrafine-grained (UFG) samples of the Al-Cu-Mg-Si aluminum alloy processed by high pressure torsion (HPT) at various temperatures. Application of the HPT treatment led to strong grain refinement, as well as to a raise of the mean-root square strains and dynamic precipitation. In case of optimal HPT treatment the UFG samples have demonstrated the enhanced thermal stability, an increase in ultimate tensile strength in 2.5 times and enhancement in fatigue endurance limit by 20 % in comparison with coarse-grained alloy subjected to standard treatment. It is shown that the regime of the HPT treatment governs the volume fraction of precipitates and segregations, thereby affecting a grain size and thermal stability of ultrafine-grained structure.

scholarly journals Thermal Stability of Nanocrystalline Structure In X37CrMoV5-l Steel

2015 ◽  
Vol 60 (1) ◽  
pp. 511-516 ◽  
Author(s):  
E. Skołek ◽  
S. Marciniak ◽  
W.A. Świątnicki
Keyword(s):  
Thermal Stability ◽  
Retained Austenite ◽  
Volume Fraction ◽  
Bainitic Ferrite ◽  
Nanocrystalline Structure ◽  
Thin Layers ◽  
Isothermal Quenching ◽  
Initial Stage ◽  
Increasing Temperature ◽  
Thermal Stability Of

AbstractThe aim of the study was to investigate the thermal stability of the nanostructure produced in X37CrMoV5-1 tool steel by austempering heat treatment consisted of austenitization and isothermal quenching at the range of the bainitic transformation. The nanostructure was composed of bainitic ferrite plates of nanometric thickness separated by thin layers of retained austenite. It was revealed, that the annealing at the temperature higher than temperature of austempering led to formation of cementite precipitations. At the initial stage of annealing cementite precipitations occurred in the interfaces between ferritic bainite and austenite. With increasing temperature of annealing, the volume fraction and size of cementite precipitations also increased. Simultaneously fine spherical Fe7C3carbides appeared. At the highest annealing temperature the large, spherical Fe7C3carbides as well as cementite precipitates inside the ferrite grains were observed. Moreover the volume fraction of bainitic ferrite and of freshly formed martensite increased in steel as a result of retained austenite transformation during cooling down to room temperature.

Sign in / Sign up

Export Citation Format

Share Document