Gas Pressure Forming of Amorphous Fe78Si9B13 Alloy

2007 ◽  
Vol 551-552 ◽  
pp. 575-580
Author(s):  
Xi Feng Li ◽  
Kai Feng Zhang ◽  
Wen Bo Han ◽  
Guo Feng Wang
Keyword(s):  
Crystallization Temperature ◽  
Deformation Behavior ◽  
Amorphous Ribbon ◽  
Superplastic Forming ◽  
Gas Pressure ◽  
Experimental Temperature ◽  
Dome Height ◽  
Ribbon Thickness ◽  
Temperature Range ◽  
Experimental Temperature Range

The deformation behavior of gas pressure forming of amorphous Fe78Si9B13 alloy was investigated under equibiaxial tension. The gas pressure forming was carried out in the temperature range of 430°C~530°C below the crystallization temperature Tx and die apertures of 5mm~10mm. The dome height and amorphous ribbon thickness of deformed specimens at the pole was measured. It was found that amorphous Fe78Si9B13 alloy had exhibited good plasticity in the experimental temperature range. The near-semisphere specimens of the radius 5mm and the height 4.5mm were obtained from the gas-pressure forming at 450°C and 530°C for 30min, which is similar to the superplastic forming.

scholarly journals A Preliminary Experiment of Non-Catalytic Transesterification: Thermal Analysis of Palm Oil and Biodiesel at Different Ratio

2018 ◽  
Vol 7 (4.35) ◽  
pp. 190
Author(s):  
Mei Yin Ong ◽  
Bello Salman ◽  
Nor-Insyirah SAL ◽  
Refal Hussein ◽  
Saifuddin Nomanbhay
Keyword(s):  
Thermal Degradation ◽  
Palm Oil ◽  
High Energy ◽  
Microwave Energy ◽  
Biodiesel Production ◽  
Experimental Temperature ◽  
External Energy ◽  
Temperature Range ◽  
Experimental Temperature Range ◽  
Subcritical Condition

Currently, the biodiesel production technology is moving toward the trend of non-catalytic reaction under subcritical condition as the conventional non-catalytic transesterification requires high energy input and high production cost. Hence, non-catalytic biodiesel production under subcritical condition using microwave energy is proposed. Before that, thermogravimetric analysis (TGA) was conducted to characterize the biodiesel feedstock and determine the suitable experimental temperature range for the proposed method. Besides, the thermal behavior of the palm oil and biodiesel at different stages of reaction was also investigated. The results showed that the palm oil and biodiesel were started to degrade from 335ºC and 160ºC respectively. However, the degradation point of palm oil was higher than the supercritical temperature of DMC. So, external energy is needed to bring down the operating condition, such as microwave energy as it has potential to reduce the activation energy. To further eliminate the problem of biodiesel thermal degradation during the transesterification process, the suggested experimental temperature range is within 80ºC to 180ºC, which is from the temperature lower than the boiling point of DMC (<90ºC) to the temperature slightly higher than the biodiesel thermal degradation point. Furthermore, DSC result indicated that palm oil requires 518.35kJ/mol to decompose.

Solvolysis of Sulphonyl Halides. II. The Alcoholysis of Aromatic Sulphonyl Chlorides in Ethanol-Acetone and Methanol-Acetone

1961 ◽  
Vol 14 (2) ◽  
pp. 205 ◽  
Author(s):  
FE Jenkins ◽  
AN Hambly
Keyword(s):  
Experimental Temperature ◽  
Isokinetic Temperature ◽  
Reaction Conditions ◽  
Temperature Range ◽  
Experimental Temperature Range

The solvolysis of aromatic sulphonyl chlorides in methanol-acetone and ethanol-acetone shows only small, irregular effects due to para-substituents because the experimental temperature range is close to the isokinetic temperature. The modification of reaction conditions in SN2 substitutions, so that the isokinetic condition is brought into the experimental temperature range, is discussed. Rates for methanolysis are lower than those for hydrolysis and are about four times the rates for the corresponding ethanolysis reactions.

An isokinetic relationship in the oxidation of acetals by ozone. Evidence for rotation before the oxidation of acyclic acetals

1979 ◽  
Vol 57 (23) ◽  
pp. 3041-3046 ◽  
Author(s):  
Roland J. Taillefer ◽  
Shirley E. Thomas ◽  
Yves Nadeau ◽  
Helmut Beierbeck
Keyword(s):  
Conformational Change ◽  
Rate Constants ◽  
Second Order ◽  
Experimental Temperature ◽  
Isokinetic Temperature ◽  
Isokinetic Relationship ◽  
Cyclic Acetals ◽  
Temperature Range ◽  
Order Rate ◽  
Experimental Temperature Range

Second order rate constants for the oxidation by ozone of several acyclic acetals of heptaldehyde were determined at several temperatures. An isokinetic relationship is shown to exist for this series of reactions and the isokinetic temperature was found to be below the experimental temperature range, a domain of temperatures where reactivity is dominated by entropy factors. These results are contrasted with those obtained for cyclic acetals of heptaldehyde, where the isokinetic temperature falls above the working temperatures, a domain of temperatures where reactivity depends mainly on enthalpy factors. These results are interpreted in terms of a conformational change before oxidation in the acyclic acetals.

A comparison of two empirical pKa(T) equations from 298 to 448 K for 2,9-Dimethyl-1,10-phenanthroline

1978 ◽  
Vol 31 (5) ◽  
pp. 1145 ◽  
Author(s):  
RD Alexander
Keyword(s):  
Experimental Temperature ◽  
Temperature Range ◽  
Experimental Temperature Range

The two most commonly used three-term equation1,2 describing the variation of pKa with temperature are compared over the range 298-448 K for 2,9-dimethyl-1,10-phenanthroline. Both equations represent the data equally well over the experimental temperature range. First-difference calculations and the Σ-plot method are used to fit the data.

The reaction of amorphous Ni-Nb films with Si in the presence of a native SiO2 layer

1990 ◽  
Vol 48 (4) ◽  
pp. 664-665
Author(s):  
N. Rozhanski ◽  
A. Barg
Keyword(s):  
High Temperature ◽  
Crystallization Temperature ◽  
Diffusion Barriers ◽  
Sio2 Layer ◽  
Si Substrate ◽  
Cross Sectional ◽  
Plan View ◽  
Temperature Range ◽  
Sputter Deposited

Amorphous Ni-Nb alloys are of potential interest as diffusion barriers for high temperature metallization for VLSI. In the present work amorphous Ni-Nb films were sputter deposited on Si(100) and their interaction with a substrate was studied in the temperature range (200-700)°C. The crystallization of films was observed on the plan-view specimens heated in-situ in Philips-400ST microscope. Cross-sectional objects were prepared to study the structure of interfaces.The crystallization temperature of Ni5 0 Ni5 0 and Ni8 0 Nb2 0 films was found to be equal to 675°C and 525°C correspondingly. The crystallization of Ni5 0 Ni5 0 films is followed by the formation of Ni6Nb7 and Ni3Nb nucleus. Ni8 0Nb2 0 films crystallise with the formation of Ni and Ni3Nb crystals. No interaction of both films with Si substrate was observed on plan-view specimens up to 700°C, that is due to the barrier action of the native SiO2 layer.

The effect of cooling rate on crystallization behavior and tensile properties of CF/PEEK composites

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Guangming Dai ◽  
Lihua Zhan ◽  
Chenglong Guan ◽  
Minghui Huang
Keyword(s):  
Cooling Rate ◽  
Crystallization Temperature ◽  
Crystallization Behavior ◽  
Crystalline Polymer ◽  
Scanning Calorimetry ◽  
Nonisothermal Crystallization ◽  
Cooling Rates ◽  
Control Range ◽  
Temperature Range ◽  
Transverse Tensile

Abstract In this study, the differential scanning calorimetry (DSC) tests were performed to measure the nonisothermal crystallization behavior of carbon fiber reinforced polyether ether ketone (CF/PEEK) composites under different cooling rates. The characteristic parameters of crystallization were obtained, and the nonisothermal crystallization model was established. The crystallization temperature range of the material at different cooling rates was predicted by the model. The unidirectional laminates were fabricated at different cooling rates in the crystallization temperature range. The results showed that the crystallization temperature range shifted to a lower temperature with the increase of cooling rate, the established nonisothermal crystallization model was consistent with the DSC test results. It is feasible to shorten the cooling control range from the whole process to the crystallization range. The crystallinity and transverse tensile strength declined significantly with the increase of the cooling rate in the crystallization temperature range. The research results provided theoretical support for the selection of cooling conditions and temperature control range, which could be applied to the thermoforming process of semi-crystalline polymer matrixed composites to improve the manufacturing efficiency.

scholarly journals The High-Temperature Deformation Behavior of As-Cast Ti90 Titanium Alloy

Metals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1630
Author(s):  
Ke Wang ◽  
Yongqing Zhao ◽  
Weiju Jia ◽  
Silan Li ◽  
Chengliang Mao
Keyword(s):  
Titanium Alloy ◽  
Deformation Behavior ◽  
Processing Map ◽  
Electron Backscatter Diffraction ◽  
Phase Region ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Two Phase ◽  
Temperature Range ◽  
Β Phase

Isothermal compressions of as-cast near-α Ti90 titanium alloy were carried out on a Gleeble-3800 simulator in the temperature range of 860–1040 °C and strain rates of 0.001–10 s−1. The deformation behavior of the alloy was characterized based on the analyses of flow curves, the constructions of Arrhenius constitutive equations and the processing map. The microstructure evolution of the alloy was analyzed using the optical microscopic (OM), transmission electron microscope (TEM), and electron backscatter diffraction (EBSD) techniques. The results show that the kinking and dynamic globularization of α lamellae is the dominant mechanism of flow softening in the α + β two-phase region, while the dynamic recovery (DRV) of β phase is the main softening mechanism in the β single-phase region. The dynamic globularization of α lamellae is mainly caused by the wedging of β phase into α laths and the shearing of α laths due to imposed shear strain. The activation of prismatic and pyramidal slip is found to be easier than that of basic slip during the deformation in the α + β two-phase region. In addition, the Schmid factor of equiaxial α is different from that of lamellar α, which also varies with the angle between its geometric orientation and compression direction (CD). Based on the processing map, the low η region within the temperature range of 860–918 °C with a strain rate range of 0.318–10 s−1 should be avoided to prevent the occurrence of deformation instability.

Plastic Deformation of Mo(Si,Al)2 Single Crystals with the C40 Structure

1996 ◽  
Vol 460 ◽  
Author(s):  
M. Moriwaki ◽  
K. Ito ◽  
H. Inui ◽  
M. Yamaguchi
Keyword(s):  
Single Crystals ◽  
Deformation Behavior ◽  
Basal Slip ◽  
Room Temperature ◽  
Slip Systems ◽  
Temperature Range ◽  
Al Content ◽  
Partial Dislocations ◽  
Increasing Temperature ◽  
Critical Resolved Shear Stress

ABSTRACTThe deformation behavior of single crystals of Mo(Si,Al)2 with the C40 structure has been studied as a function of crystal orientation and Al content in the temperature range from room temperature to 1500°C in compression. Plastic flow is possible only above 1100°C for orientations where slip along <1120> on (0001) is operative and no other slip systems are observed over whole temperature range investigated. The critical resolved shear stress for basal slip decreases rapidly with increasing temperature and the Schmid law is valid. Basal slip appears to occur through a synchroshear mechanism, in which a-dislocations (b=1/3<1120>) dissociate into two synchro-partial dislocations with the identical Burgers vector(b*1/6<1120>) and each synchro-partial further dissociates into two partials on two adjacent planes.

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