Mechanical properties and strengthening effects of in situ (TiB+TiC)/Ti-1100 composite at elevated temperatures

2016 ◽  
Vol 654 ◽  
pp. 352-358 ◽  
Author(s):  
Fengcang Ma ◽  
Tianran Wang ◽  
Ping Liu ◽  
Wei Li ◽  
Xinkuan Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperatures

Fabrication of Aluminum/Aluminum Nitride Composites by Reactive Mechanical Alloying

2007 ◽  
Vol 534-536 ◽  
pp. 181-184
Author(s):  
Seung Hoon Yu ◽  
Kwang Seon Shin
Keyword(s):  
Mechanical Properties ◽  
Mechanical Alloying ◽  
Elevated Temperatures ◽  
Hot Extrusion ◽  
Extrusion Process ◽  
Processing Technique ◽  
Compression Tests ◽  
Composite Powders ◽  
Al Matrix Composites

Various reactions and the in-situ formation of new phases can occur during the mechanical alloying process. In the present study, Al powders were strengthened by AlN, using the in-situ processing technique during mechanical alloying. Differential thermal analysis and X-ray diffraction studies were carried out in order to examine the formation behavior of AlN. It was found that the precursors of AlN were formed in the Al powders and transformed to AlN at temperatures above 600oC. The hot extrusion process was utilized to consolidate the composite powders. The composite powders were canned in an Al can and then extruded at elevated temperatures. The microstructure of the extrusions was examined by SEM and TEM. In order to investigate the mechanical properties of the extrusions, compression tests and hardness measurements were carried out. It was found that the mechanical properties and the thermal stability of the Al/AlN composites were significantly greater than those of conventional Al matrix composites.

Two-Dimensional Mapping of the Mechanical Properties of Pb-Free Solders for Reliability Optimization

2009 ◽  
Vol 6 (3) ◽  
pp. 182-185
Author(s):  
V. Marques ◽  
C. Johnston ◽  
P.S. Grant
Keyword(s):  
Mechanical Properties ◽  
Solder Joint ◽  
Elevated Temperatures ◽  
Constitutive Models ◽  
Processing Temperature ◽  
Reliability Optimization ◽  
Two Dimensional ◽  
Free Solder ◽  
Dimensional Mapping

The development of thermomechanical models of Pb-free solders is more complex than for Pb-Sn solders as a result of their higher reactivity and processing temperature that leads to the continuous evolution of stiff and angular intermetallics in the microstructure. In this paper, nanoindentation has been explored for its potential to characterize mechanically the complex microstructure of Pb-free solder joints. Hardness and Young's modulus of the various microphases in a Sn-Ag-Cu/Cu solder joint were characterized at 25°C and averages were obtained from nanoindentation maps composed of 100–200 indentations. The possibility to map mechanical property gradients across the various solder joint interfaces and to differentiate between different presentations of the same phase, including in situ at elevated temperatures, has been suggested to be useful in extending the available data for constitutive models used in reliability simulations of Pb-free solders.

Microstructures and Mechanical Properties of NiAl+Mo In-Situ Eutectic Composites

1990 ◽  
Vol 194 ◽  
Author(s):  
P. R. Subramanian ◽  
M. G. Mendiratta ◽  
D. B. Miracle ◽  
D. M. Dimiduk
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Room Temperature ◽  
Composite System ◽  
Elevated Temperatures ◽  
Two Phase ◽  
Structural Applications ◽  
Temperature Fracture

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.

scholarly journals Influence of curing temperature and stress conditions on mechanical properties of cementing paste backfill

2016 ◽  
Vol 53 (1) ◽  
pp. 148-161 ◽  
Author(s):  
Megan L. Walske ◽  
Heather McWilliam ◽  
James Doherty ◽  
Andy Fourie
Keyword(s):  
Mechanical Properties ◽  
Effective Stress ◽  
Elevated Temperatures ◽  
Small Strain ◽  
Curing Temperature ◽  
Temperature Conditions ◽  
In Situ Conditions ◽  
Paste Backfill ◽  
Temperature Controlled

Cemented paste backfill (CPB) has been observed to achieve greater cemented strength when cured in situ compared with equivalent mixes cured and tested in a laboratory environment. This is in part due to the development of effective stress and generation of elevated temperatures by exothermic cement hydration reactions occurring during curing in a typical underground stope environment. This differs from curing in typical laboratory environments, where little or no effective stresses are generated and curing occurs under constant-temperature conditions. This paper outlines the development, calibration, and testing of a temperature-controlled hydration cell that provides closer representation of in situ conditions by controlling the rate and final amount of specimen temperature increase, in addition to curing under effective stress. The temperature-controlled hydration cell was used to examine the effect of curing under combined effective stress and temperature conditions on the development of small-strain stiffness over a 7 day curing period and the unconfined compressive strength at the end of this period. Curing with both elevated temperature and effective stress was found to significantly increase the mechanical properties of CPB compared with curing at elevated effective stress or ambient temperatures alone.

scholarly journals In Situ Formation of TiB2 in Fe-B System with Titanium Addition and Its Influence on Phase Composition, Sintering Process and Mechanical Properties

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4188
Author(s):  
Mateusz Skałoń ◽  
Marek Hebda ◽  
Benedikt Schrode ◽  
Roland Resel ◽  
Jan Kazior ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Phase Composition ◽  
Elevated Temperatures ◽  
Thermodynamic Calculations ◽  
X Ray Diffraction ◽  
Titanium Addition ◽  
Titanium Borides ◽  
Hard And Brittle Material ◽  
In Situ Formation

Interaction of iron and boron at elevated temperatures results in the formation of an E (Fe + Fe2B) eutectic phase that plays a great role in enhancing mass transport phenomena during thermal annealing and therefore in the densification of sintered compacts. When cooled down, this phase solidifies as interconnected hard and brittle material consisting of a continuous network of Fe2B borides formed at the grain boundaries. To increase ductile behaviour, a change in precipitates’ stoichiometry was investigated by partially replacing iron borides by titanium borides. The powder of elemental titanium was introduced to blend of iron and boron powders in order to induce TiB2 in situ formation. Titanium addition influence on microstructure, phase composition, density and mechanical properties was investigated. The observations were supported with thermodynamic calculations. The change in phase composition was analysed by means of dilatometry and X-ray diffraction (XRD) coupled with thermodynamic calculations.

scholarly journals Mechanical Properties of Thixoforged In Situ Mg2Sip/AM60B Composite at Elevated Temperatures

Metals ◽  
2018 ◽  
Vol 8 (2) ◽  
pp. 106 ◽  
Author(s):  
Suqing Zhang ◽  
Tijun Chen ◽  
Jixue Zhou ◽  
Dapeng Xiu ◽  
Tao Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperatures

Properties of Hot-Pressed Cr-Cr3Si

1994 ◽  
Vol 364 ◽  
Author(s):  
Joseph W. Newkirk ◽  
Joseph E. Price
Keyword(s):  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Low Temperature ◽  
High Temperatures ◽  
Hot Pressing ◽  
Elevated Temperatures ◽  
Arc Melting ◽  
Cast Alloys ◽  
Strength And Toughness

AbstractPreviously, Cr-Cr3Si in-situ composites produced by arc-melting were shown to have good strengths at high temperatures1. For example, samples of a 25% Cr and 75% Cr3Si composite achieved bend strengths of 135 MPa at 1200°C. However, there is potential for even higher strengths at high temperatures and a need for improvement in the low temperature strength and toughness. In order to improve the properties, two approaches were taken. The first used powder metallurgy to develop a better microstructure than in the cast alloys, to try to improve both strength and toughness. The second approach was to incorporate erbia into the composites, to improve the strength and stability of the microstructure at elevated temperatures.High density samples of hot pressed Cr-15.5Si and Cr-18.6Si have been produced by mixing Cr and Gr3Si powders and hot pressing in a graphite die. Erbia powders have been incorporated into some compacts for comparison.Micros true tures have been characterized and mechanical properties determined. Both the hot pressing and the erbia affected the properties. In addition the erbia had a significant effect on consolidation of the samples.

Контроль и определение параметров сварной низкоуглеродистой стали E 6013 с помощью ультразвукового контроля и преобразования Гильберта—Хуанга

2021 ◽  
pp. 64-70
Author(s):  
Аиша Халид ◽  
М.Газанфар Али ◽  
Тарик Майрадж Русул Хан ◽  
Мухаммад Имран ◽  
Салман Низар ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Ultrasonic Testing ◽  
Elevated Temperatures ◽  
Quantitative Relation ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Hilbert Huang Transform ◽  
Processing Techniques ◽  
Non Destructive

All welded parts undergo aging once operated at elevated temperatures. Exposures of structures on elevated temperatures adversely affect the material performance and deteriorate the structure’s toughness. The welded part also develops the high risk of brittle fracture. In order to establish the fracture toughness, it is not always possible to remove the specimen from the service. Therefore, it is desirable to develop an In-situ Non-destructive testing (NDT) based on Ultrasonic Testing (UT) method along with advanced signal processing techniques. Ultrasonic Testing (UT) is an extensively used Non-destructive testing technique that offers improved damage detection capability. The objective of the study is to found a quantitative relation between UT and mechanical properties of welded joint heat treated specimens. The data was acquired from the testing of weld specimens at different levels of temperatures through UT testing. There is a trend observed between the variation in the UT signal’s characteristics i.e. attenuation and the variation in the mechanical properties. The likely categorization of UT signal in terms of different thermal aging levels has also been explored using Hilbert Huang Transform (HHT) on acquired UT signals. The experimental relationships will enable welded specimen toughness prediction solely through in-situ UT testing while the specimen will remain in service.

Mechanical Properties and Dislocation Structure of Single Crystal Cdte Deformed in Compression at 300°C

1976 ◽  
Vol 34 ◽  
pp. 592-593
Author(s):  
Ernest L. Hall ◽  
J. B. Vander Sande
Keyword(s):  
Mechanical Properties ◽  
Single Crystal ◽  
Dislocation Structure ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Strain Curve ◽  
Optical Devices ◽  
Semiconductor Compound ◽  
Wide Range ◽  
Sample Orientation

The present paper describes research on the mechanical properties and related dislocation structure of CdTe, a II-VI semiconductor compound with a wide range of uses in electrical and optical devices. At room temperature CdTe exhibits little plasticity and at the same time relatively low strength and hardness. The mechanical behavior of CdTe was examined at elevated temperatures with the goal of understanding plastic flow in this material and eventually improving the room temperature properties. Several samples of single crystal CdTe of identical size and crystallographic orientation were deformed in compression at 300°C to various levels of total strain. A resolved shear stress vs. compressive glide strain curve (Figure la) was derived from the results of the tests and the knowledge of the sample orientation.

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