A Cryostat for Tensile Tests in the Temperature Range 300° to 4°K

1962 ◽  
pp. 448-454 ◽  
Author(s):  
R. P. Reed
Keyword(s):  
Tensile Tests ◽  
Temperature Range

Formability and Process Conditions of Magnesium Alloy Sheets

2005 ◽  
Vol 488-489 ◽  
pp. 453-456 ◽  
Author(s):  
Shi Hong Zhang ◽  
Yong Chao Xu ◽  
G. Palumbo ◽  
S. Pinto ◽  
Luigi Tricarico ◽  
...  
Keyword(s):  
Deep Drawing ◽  
Tensile Tests ◽  
Process Conditions ◽  
Drawing Ratio ◽  
Temperature Range ◽  
Fine Grained ◽  
Axial Tensile ◽  
Die Surface ◽  
Lower Temperature Range ◽  
Lower Temperature

Comparing the formability with each other, extrusion and various rolling experiments were carried out to make fine-grained AZ31 Mg sheets, and uni-axial tensile tests were carried out at different strain rates and temperatures to investigate the effect of different variables. A warm deep drawing tool setup with heating elements, which were distributed under the die surface and inside the blank holder, was designed and manufactured, and deep drawing was performed. Extruded Mg alloy AZ31 sheets exhibit the best deep drawing ability when working in the temperature range 250-350°C. Extruded and rolled sheets of 0.8 mm thick were also deep drawn in the lower temperature range 105-170°C，showing good formability and reaching a Limit Drawing Ratio up to 2.6 at 170°C for rolled sheets. At last, a sheet cup 0.4 mm thick was deep drawn successfully at 170 °C.

scholarly journals Microstructural Characterization and Mechanical Properties of L-PBF Processed 316 L at Cryogenic Temperature

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5856
Author(s):  
Pragya Mishra ◽  
Pia Åkerfeldt ◽  
Farnoosh Forouzan ◽  
Fredrik Svahn ◽  
Yuan Zhong ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cryogenic Temperature ◽  
Room Temperature ◽  
Mechanical Performance ◽  
Microstructural Characterization ◽  
Tensile Tests ◽  
Phase Changes ◽  
X Ray Diffraction ◽  
Temperature Range ◽  
Aerospace Applications

Laser powder bed fusion (L-PBF) has attracted great interest in the aerospace and medical sectors because it can produce complex and lightweight parts with high accuracy. Austenitic stainless steel alloy 316 L is widely used in many applications due to its good mechanical properties and high corrosion resistance over a wide temperature range. In this study, L-PBF-processed 316 L was investigated for its suitability in aerospace applications at cryogenic service temperatures and the behavior at cryogenic temperature was compared with room temperature to understand the properties and microstructural changes within this temperature range. Tensile tests were performed at room temperature and at −196 °C to study the mechanical performance and phase changes. The microstructure and fracture surfaces were characterized using scanning electron microscopy, and the phases were analyzed by X-ray diffraction. The results showed a significant increase in the strength of 316 L at −196 °C, while its ductility remained at an acceptable level. The results indicated the formation of ε and α martensite during cryogenic testing, which explained the increase in strength. Nanoindentation revealed different hardness values, indicating the different mechanical properties of austenite (γ), strained austenite, body-centered cubic martensite (α), and hexagonal close-packed martensite (ε) formed during the tensile tests due to mechanical deformation.

The hot ductility behaviour of C—Mn—Nb—Al steels and its relation to crack propagation during the straightening of concast strand

1980 ◽  
Vol 295 (1413) ◽  
pp. 124-124
Keyword(s):  
Crack Propagation ◽  
Beneficial Effect ◽  
Surface Crack ◽  
Base Composition ◽  
Tensile Tests ◽  
Hot Ductility ◽  
Percentage Reduction ◽  
Temperature Range ◽  
Solution Treated ◽  
Reduction In Area

As most continuous casters used curved moulds, the as-cast strand must have sufficient hot ductility to survive the straightening operation without cracking. The influence of composition on the tendency for surface crack propagation to occur on straightening of concast strand of a commercial C—Mn-Nb-Al grade of steel, has been examined and compared with the hot ductility behaviour as measured by Gleeble tensile tests. Samples of steel with a nominal base composition of 0.15% C, 1.4% Mn, 0.03% Nb, 0.005 % N but having soluble A1 in the range < 0.01-0.07 % and P in the range 0.01-0.03 % have been solution treated to 1330 °C, cooled to test temperature and strained to fracture in the temperature range 1000-700 °C. The percentage reduction in area passed through a minimum in the temperature range 750-800 °C. Of the elements examined, soluble A1 was found to be the most deleterious to ductility for test temperatures above 850 °C. The niobium addition tended to reduce hot ductility most significantly for temperatures below 850 °C. Phosphorus, surprisingly, was found to have a small beneficial effect on hot ductility.

A COMPARATIVE STUDY OF STRESS RELAXATION RATE IN UNIRRADIATED AND IRRADIATED PURE TITANIUM AT LOW TEMPERATURES

2007 ◽  
Vol 21 (31) ◽  
pp. 5247-5255 ◽  
Author(s):  
I. M. GHAURI ◽  
KARRAR HAIDER ◽  
NAVEED AFZAL ◽  
S. A. SIDDIQUE
Keyword(s):  
Stress Relaxation ◽  
Relaxation Rate ◽  
Testing Machine ◽  
Pure Titanium ◽  
Tensile Tests ◽  
Temperature Range ◽  
Radiation Induced ◽  
Mechanical Twins ◽  
Induced Defects ◽  
The Given

Stress relaxation rate in unirradiated and electron-beam-irradiated polycrystalline titanium (99.994%) was studied in the temperature range 300–100 K. Titanium specimens were irradiated with 12 MeV electrons to a dose of 0.01 dpa for 12 min. at 300 K. Tensile tests of the specimens were performed using a Universal Testing Machine in the given temperature range. To measure the relaxation of stress with time, the crosshead of the machine was arrested at different fixed loads. Stress relaxation rate s for a given stress level σ0 was found to be temperature dependent, i.e., it decreased with decreasing temperature both in unirradiated and irradiated specimens. However, the decrease was more pronounced in irradiated specimens than that of unirradiated ones. The observed decrease in s values with decrease in temperature is ascribed to the retarding effect of unrelaxed dislocations pinned at defects, especially at the twin boundaries in the course of deformation, which became more conspicuous in irradiated specimens due to the interaction of glide dislocations with radiation-induced defects, in addition to mechanical twins. The activation energy for the movement of dislocations, calculated using the single-barrier model of stress relaxation, was found to be higher in irradiated specimens than that of unirradiated ones at all test temperatures.

Precipitation Sequence and Kinetics in an Fe-Si-Ti Alloy

2011 ◽  
Vol 172-174 ◽  
pp. 833-838 ◽  
Author(s):  
Malika Perrier ◽  
Alexis Deschamps ◽  
Patricia Donnadieu ◽  
Frédéric de Geuser ◽  
Frédéric Danoix ◽  
...  
Keyword(s):  
Volume Fraction ◽  
High Volume ◽  
Tensile Tests ◽  
Atom Probe ◽  
Precipitate Size ◽  
Precipitation Sequence ◽  
Precipitation Kinetics ◽  
Temperature Range ◽  
Transmission Electron ◽  
Temporary Decrease

The Fe-Si-Ti system is known to show nanoscale precipitation of the Fe2SiTi Heusler phase with potentially high volume fraction (~4%), very high density and a size ranging from 1 to 20nm after artificial aging. The strong hardening potential of these precipitates make these steels candidates for automotive applications; however no understanding of the precipitation sequence (competition with other phases) nor the precipitation kinetics are available. The present study presents a quantitative study of the precipitation kinetics (size, volume fraction and number density) in a wide temperature range (450-800°C), realised by coupling systematically Small Angle Neutron Scattering (SANS), Transmission Electron microscopy (TEM) and Tomographic Atom Probe (TAP). Tensile tests were also carried out so as to determine the microstructure/properties relationships. Along the complete temperature range, it is shown that a compromise between time for precipitation and small precipitate sizes can be reached around 550°C. At this intermediate temperature, precipitation is shown to occur in two steps, linked with a second nucleation process after nucleation & growth of the first family of Fe2SiTi has been completed. This second precipitation step results in a temporary decrease in precipitate size and an increase in hardness. The nature of these precipitates is discussed in view of the TEM and TAP observations.

Rupture of Rubber. VII. Effect of Rate of Extension in Tensile Tests

1961 ◽  
Vol 34 (1) ◽  
pp. 76-84 ◽  
Author(s):  
H. W. Greensmith
Keyword(s):  
Tensile Strength ◽  
Wide Temperature Range ◽  
Tensile Tests ◽  
Subsequent Paper ◽  
Not Given ◽  
Temperature Range ◽  
Extensive Data ◽  
Extension Curve ◽  
Similar Range

Abstract There are few published measurements on the effect of rate of extension in tensile rupture tests on rubber vulcanizates. The most extensive data on a single vulcanizate are those of Dogadkin and Sandomirskii˘ and of Smith. These measurements were made on GR-S gum vulcanizates and covered a similar range of rates of extension, from about 0.02 to 20%/sec. Ring specimens were used in both cases, and tensile strength and breaking extension were measured over a wide temperature range. Villars has made tensile strength and breaking extension measurements on double dumbbell specimens of several gum and filled vulcanizates extended at various rates in the range 10,000 to 100,000%/sec. Kainradl and Handler have reported tensile strength measurements for several filled vulcanizates, obtained with dumbbell specimens extended at four different rates of extension covering a range from about 1 to 100,000%/sec. All these results indicate that tensile strength and breaking extension can vary appreciably with the rate of extension of the specimen. Complete load-extension curves are not given in any of these papers. In the present paper an autographic method is described for obtaining the load-extension curves of ring specimens extended at various rates from about 0.1 to 2000%/sec. Results showing the effect of the rate of extension on the tensile strength and breaking extension and on the load-extension curve are given for GR-S vulcanizates. The data were obtained primarily for the comparisons of tear and tensile rupture measurements given in a subsequent paper (Part VIII).

Tensile tests of Fe70Al30 in a TEM in the temperature range of the yield stress anomaly

1995 ◽  
Vol 192-193 ◽  
pp. 793-798 ◽  
Author(s):  
H. Rösner ◽  
G. Molénat ◽  
M. Kolbe ◽  
E. Nembach
Keyword(s):  
Yield Stress ◽  
Tensile Tests ◽  
Temperature Range

scholarly journals Mechanical Behavior of Inconel 625 at Elevated Temperatures

2018 ◽  
Author(s):  
Mauro M. de Oliveira ◽  
Antônio A. Couto ◽  
Gisele F. C. Almeida ◽  
Danieli A. P. Reis ◽  
Nelson B. de Lima ◽  
...  
Keyword(s):  
Elevated Temperatures ◽  
Aging Effect ◽  
Tensile Tests ◽  
Constant Load ◽  
Anomalous Behavior ◽  
Inconel 625 ◽  
Dynamic Strain ◽  
Intergranular Cracking ◽  
Creep Tests ◽  
Temperature Range

Abstract: The Inconel 625 is a nickel-based alloy has been widely used in the high-temperature application. The Inconel 625 exhibits unstable plastic flow at elevated temperature characterized by serrated yielding, known as Portevin-Le Chatelier effect. The aim of this work is to evaluate the mechanical properties at high temperatures of the Inconel 625. The tensile tests were performed in the temperature range of room temperature until 1000 °C and strain rate of 2x10^-4 to 2x10^-3 s^-1. The creep tests were performed in the temperature range of 600-700 °C, in the stress range of 500-600 MPa in a constant load mode. The surface fracture was observed by optical and scanning electron microscopy. Serrated stress-strain behavior was observed in the curves obtained at 200 to 700 °C, which was associated with the dynamic strain aging effect. The yield strength and the elongation values show an anomalous behavior as a function of the test temperature. An intergranular cracking was observed specimen tensile tested at 500 °C that can be attributed to the decohesion of the carbides along the grain boundaries. The fracture surface of the specimen tensile tested at 700 °C showed the predominance of transgranular cracking with tear dimples with a parabolic shape.

Kinetics of Sigma Phase Precipitation in Niobium-Stabilized Austenitic Stainless Steel and Effect on the Mechanical Properties

2014 ◽  
Vol 783-786 ◽  
pp. 848-853 ◽  
Author(s):  
Xavier Ledoux ◽  
Francois Buy ◽  
Aurélien Perron ◽  
Eric Suzon ◽  
José Farré ◽  
...  
Keyword(s):  
Sigma Phase ◽  
Formation Rate ◽  
Austenitic Stainless Steels ◽  
Tensile Tests ◽  
Metallographic Analysis ◽  
Delta Ferrite ◽  
Temperature Range ◽  
Δ Ferrite ◽  
Temperature Transformation ◽  
Kinetics Of

Stabilized austenitic stainless steels are widely used in nuclear and oil industries. The 316 Nb steel grade presented in this study holds a small amount of delta ferrite in the austenitic matrix which tends to transform into sigma phase during prolonged exposures in the temperature range of 600-1000°C. Sigma phase is promoted by ferritic elements such as chromium, molybdenum, niobium and silicon. Time-Temperature-Transformation (TTT) diagram of the δ-ferrite evolution is established thanks to DSC experiments and quantitative metallographic analysis. It is observed that the highest sigma phase formation rate occurs between 800 and 900°C, and that the transformation of ferrite begins after a few minutes of exposure in this temperature range. The microstructure of transformed δ-ferrite is mostly dominated by the eutectoid mixture σ + γ2. Tensile tests were performed for three different cooling conditions: a significant embrittlement attributed to the δ-ferrite transformation is measured by a ductility loss for the lowest cooling rate.

The Mechanical Properties of A Ni-30Al-2OFe-0.05Zr Intermetallic Alloy in the Temperature Range 300–1200 K.

1990 ◽  
Vol 213 ◽  
Author(s):  
S. V. Raj ◽  
R. D. Noebe ◽  
I. E. Locci
Keyword(s):  
Electron Microscopy ◽  
Tensile Tests ◽  
Critical Stress Intensity Factor ◽  
Intermetallic Alloy ◽  
Transgranular Cleavage ◽  
Optical Scanning ◽  
Temperature Range ◽  
Linear Elastic ◽  
Transmission Electron ◽  
Elastic Fracture

ABSTRACTTensile tests were conducted on an extruded Ni-30(at.%)Al-20Fe-0.05Zr intermetallic alloy in the temperature range 300–1200 K and the microstructures were characterized by optical, scanning and transmission electron microscopy. The alloy did not exhibit any room temperature ductility and failed by transgranular cleavage at a stress of about 710 MPa. This mode of fracture was observed at and below 873 K with the total ductility being less than 2.5%. However, the failure mode changed to dimpled fracture, triple point cracking and rupture above 873 K. Scanning electron microscopy of the fracture surfaces revealed that transgranular cleavage failure had always originated at pre-existing defects. In these cases, the fracture stress exhibited a good correlation with the defect size in accordance with linear elastic fracture mechanics, where the critical stress intensity factor was estimated to be about 4 MPa m1/2.

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