Investigation on a Novel Low Temperature/Vacuum Bag Cure Prepreg

2007 ◽  
Vol 546-549 ◽  
pp. 1623-1626 ◽  
Author(s):  
Bao Yan Zhang ◽  
Bin Tai Li ◽  
Xiang Bao Chen ◽  
Zheng Gang Zhou

A low temperature cure resin has been prepared successfully by applying self designed/synthesized cure agent and commercial epoxies through slurry mixing process. Low temperature/vacuum bag cure prepreg with excellent drapeability & spreadability and over 10 days storage life at room temperature could be prepared by hot/melt technique. The cure and post cure parameters of manufacturing composites were optimized. The main properties of low temperature/vacuum bag cure composite have been determined. Results indicated that the low temperature/vacuum bag cure composite system had excellent mechanical properties and its long service temperature could reach 80°C. The influence of ultrasonic irradiation applied during the manufacturing process on the properties of the composite was discussed, and results showed that the ultrasonic irradiation improved the properties of composite greatly and suggested a novel strategy to improve the mechanical properties of low temperature cure composite systems.

2021 ◽  
Vol 2103 (1) ◽  
pp. 012075
Author(s):  
AA Dmitrievskiy ◽  
DG Zhigacheva ◽  
VM Vasyukov ◽  
PN Ovchinnikov

Abstract In this work, the phase composition (relative fractions of monoclinic m-ZrO2, tetragonal t-ZrO2, and cubic c-ZrO2 phases) and mechanical properties (hardness, fracture toughness, compressive strength) of alumina toughened zirconia (ATZ) ceramics, with an addition of silica were investigated. Calcium oxide was used as a stabilizer for the zirconia tetragonal phase. It was shown that CaO-ATZ+SiO2 ceramics demonstrate increased resistance to low-temperature degradation. The plasticity signs at room temperature were found due to the SiO2 addition to CaO-ATZ ceramics. A yield plateau appears in the uniaxial compression diagram at 5 mol. % SiO2 concentration. It is hypothesized that discovered plasticity is due to the increased t→m transformability.


2012 ◽  
Vol 443-444 ◽  
pp. 583-586
Author(s):  
Ya Juan Sun ◽  
Ri Ga Wu ◽  
Hong Jing Wang

The mechanical properties of a new Zr-based bulk metallic glass at low temperatures were investigated. The results indicate that the fracture strength increases significantly (4.9%) and the global plasticity increases somewhat when testing temperature is lowered to 123K. The stress-strain curve of the sample deformed exhibits more serrations and smaller stress drop due to formation of more shear bands at low temperature than at room temperature.


2017 ◽  
Vol 265 ◽  
pp. 456-462 ◽  
Author(s):  
P.L. Reznik ◽  
Mikhail Lobanov

Studies have been conducted as to the effect of Cu, Mn, Fe concentration changes in Al-Cu-Mn-Fe-Ti alloy, the conditions of thermal and deformational treatment of ingots and extruded rods 40 mm in diameter on the microstructure, phase composition and mechanical properties. It has been determined that changing Al-6.3Cu-0.3Mn-0.17Fe-0.15Ti alloy to Al-6.5Cu-0.7Mn-0.11Fe-0.15Ti causes an increase in the strength characteristics of extruded rods at the room temperature both after molding and in tempered and aged conditions, irrespective of the conditions of thermal treatment of the initial ingot (low-temperature annealing 420 °С for 2 h, or high-temperature annealing at 530 °С for 12 h). Increasing the extruding temperature from 330 to 480 °С, along with increasing Cu, Mn and decreasing Fe in the alloy Al-Cu-Mn-Ti, is accompanied by the increased level of ultimate strength in a quenched condition by 25% to 410 MPa, irrespective of the annealing conditions of the original ingot. An opportunity to apply the Al-6.3Cu-0.3Mn-0.17Fe-0.15Ti alloy with low-temperature annealing at 420 °С for 2 h and the molding temperature of 330 °С has been found to produce rods where, in the condition of full thermal treatment (tempering at 535 °С + aging at 200 °С for 8 hours), a structure is formed that ensures satisfactory characteristics of high temperature strength by resisting to fracture for more than 100 hours at 300 °С and 70 MPa.


2013 ◽  
Vol 35 ◽  
pp. 15-24 ◽  
Author(s):  
Robert D. Schmidt ◽  
Eldon D. Case ◽  
Gloria J. Lehr ◽  
Donald T. Morelli

2014 ◽  
Vol 783-786 ◽  
pp. 431-436 ◽  
Author(s):  
Xiao Ping Niu ◽  
Tim Skszek ◽  
Mark Fabischek ◽  
Alex Zak

Cosma R&D investigated a low temperature warm forming process by which a magnesium ZEK 100 door inner part with a single-stage draw depth of 144 mm was successfully formed. The warm forming process is comprised of three steps: 1) heating pre-lubricated blanks in an oven at temperatures ranging from 215°C to 260 °C, 2) robotic transfer of the heated blank to a mechanical stamping press, 3) forming of the panel in room temperature stamping die at speed of about 160 mm/s. The effect of process parameters on the formability of the part, as well as, the post-forming properties including the mechanical properties, microstructure evolution and deformation thinning are also presented. The result indicates that Magnesium ZEK 100 exhibits superior low temperature warm formability over Magnesium AZ31B, and the developed warm forming process is promising and potential for volume production of magnesium automotive parts.


2007 ◽  
Vol 539-543 ◽  
pp. 2100-2105
Author(s):  
Takeshi Fukami ◽  
A. Nanbu ◽  
M. Fukatani ◽  
Daisuke Okai ◽  
Y. Akeno ◽  
...  

In order to examine mechanical properties of a metallic glass Zr50Cu40Al10 in low temperature below room temperature, the temperature T dependence of mechanical resonance of ultrasonic wave are measured. The mechanical resonance frequency in an as-quenched sample shows an abrupt increase at 200K for longitudinal wave and 160 K for transverse wave with decreasing T. After this abrupt increase, the sound propagation cannot be detected below these temperatures but the wave propagation is restored with increasing T and there is an abrupt decrease at 260K for the both wave modes. The similar hysteresis is observed in temperature dependence of the electrical resistivity. These suggest a kind of structure instability of Zr50Cu40Al10 in low temperature region.


1990 ◽  
Vol 194 ◽  
Author(s):  
P. R. Subramanian ◽  
M. G. Mendiratta ◽  
D. B. Miracle ◽  
D. M. Dimiduk

AbstractThe quasibinary NiAI-Mo system exhibits a large two-phase field between NiAl and the terminal (Mo) solid solution, and offers the potential for producing in-situ eutectic composites for high-temperature structural applications. The phase stability of this composite system was experimentally evaluated, following long-term exposures at elevated temperatures. Bend strengths as a function of temperature and room-temperature fracture toughness data are presented for selected NiA1-Mo alloys, together with results from fractography observations.


2012 ◽  
Vol 468-471 ◽  
pp. 1053-1057
Author(s):  
Yun Feng Yang ◽  
Guo Sheng Hu ◽  
Xing Lin Ren

By the in situ compatibilization, PP/POE blends were prepared with dicumyl peroxide (DCP) as initiator, Trimethylolpropane triacrylate (TMPTA) as co-during systems and the metallocene polyolef in elastomers ploy (ethylene-1-octene) (POE) as toughening rubber. The effects of additive amount for TMPTA、POE on the mechanical properties were studied. The results showed that the maximum value of the room-temperature and low-temperature impact strength for the composite was reached to 52.03KJ/m2 and 37.29KJ/m2, and the elongationfor was reached to 482.74%.


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