scholarly journals Superplastic behavior of rosin/beeswax blends at room temperature

2012 ◽  
Vol 128 (5) ◽  
pp. 2713-2719 ◽  
Author(s):  
Y. Gaillard ◽  
M. Girard ◽  
G. Monge ◽  
A. Burr ◽  
E. Darque Ceretti ◽  
...  
Keyword(s):  
Room Temperature ◽  
Superplastic Behavior

Room Temperature Superplasticity in Fine/Ultrafine-Grained Zn-Al Alloys with Different Phase Compositions

2018 ◽  
Vol 385 ◽  
pp. 72-77
Author(s):  
Muhammet Demirtas ◽  
Harun Yanar ◽  
Onur Saray ◽  
Gençağa Pürçek
Keyword(s):  
Grain Size ◽  
Room Temperature ◽  
Grain Boundary Sliding ◽  
Al Alloys ◽  
Phase Boundaries ◽  
Superplastic Behavior ◽  
Al Content ◽  
Α Phase ◽  
Ultrafine Grained ◽  
Superplastic Elongation

Three Zn-Al alloys, namely Zn-22Al, Zn-5Al and Zn-0.3Al, were subjected to equal-channel angular pressing (ECAP), and the effect of ECAP on their microstructure and room temperature (RT) superplastic behavior were investigated in detail referring to previous studies reported by the authors of the current study. ECAP remarkably refined the microstructures of three alloys as compared to their pre-processed conditions. While the lowest grain size was achieved in Zn-22Al alloy as 200 nm, the grain sizes of Zn-5Al and Zn-0.3Al alloys were ~540 nm and 2 µm, respectively, after ECAP. After the formation of fine/ultrafine-grained (F/UFG) microstructures, all Zn-Al alloys exhibited superplastic behavior at RT and high strain rates. The maximum superplastic elongations were 400%, 520% and 1000% for Zn-22Al, Zn-5Al and Zn-0.3Al alloys, respectively. It is interesting to point out that the highest RT superplastic elongation was obtained in Zn-0.3Al alloy with the largest grain size, while Zn-22Al alloy having the lowest grain size showed the minimum superplastic elongation. This paradox was attributed to the different phase compositions of these alloys. The formation of Al-rich α/α phase boundaries, where grain boundary sliding is minimum comparing to Zn-rich η/η and η/α phase boundaries of Zn-Al alloys, is the lowest level in Zn-0.3Al alloy among all the alloys. Therefore, it can be concluded that if it is desired to achieve high superplastic elongation in Zn-Al alloys at RT, keeping Al content at a possibly minimum level seems to be the most suitable way.

Effects of Temperature, Strain Rate and Grain Size on Superplastic Behavior of Magnesium

2012 ◽  
Vol 488-489 ◽  
pp. 27-34 ◽  
Author(s):  
Muhammad Waseem Soomro ◽  
Thomas Rainer Neitzert
Keyword(s):  
Grain Size ◽  
Strain Rate ◽  
Magnesium Alloys ◽  
Room Temperature ◽  
Superplastic Forming ◽  
Experimental Results ◽  
Superplastic Behavior ◽  
Influence Of Temperature ◽  
Effects Of Temperature ◽  
Temperature Strain

The influence of temperature, grain size and strain rate on superplasticity of magnesium is investigated. Different approaches are compared along with their experimental results to show the variation in the amount of superplasticity by varying above mentioned parameters. At room temperature magnesium alloys usually have poor formability but recent studies of some alloys such as ZE10, AZ31, AZ61 AZ60, AZ80 and AZ91 are pointing that by varying the temperature along with grain size and strain rate improved formability is possible or even superplastic forming of these alloys can be achieved to meet the demands of automotive, aircraft and other weight conscious industries.

scholarly journals INVESTIGATION OF SUPERPLASTIC BEHAVIOR OF CERTAIN (Zn – Al) ALLOYS

2019 ◽  
Vol 18 (4) ◽  
pp. 604-615
Author(s):  
Sora H Abed ◽  
Abdul Wahid K Rajih ◽  
Ahmed O Al-Roubaiy
Keyword(s):  
Mechanical Properties ◽  
Cold Rolling ◽  
Room Temperature ◽  
Al Alloys ◽  
Al Alloy ◽  
Test Results ◽  
Superplastic Behavior ◽  
Partial Remelting ◽  
Hot Rolled ◽  
Hot Test

Super plasticity behavior finds applications in so many fields, for example the aerospacemanufacturing that is the main bazaar for super plasticity, but automotive, medical, sports,cookware and architectural applications have their share too. "In this work a study of thesuperplastic behavior of a new Zn-Al alloy was conducted. In addition to the investigation ofthe possible superplastic behavior of Zn-0.5Al alloy. These alloys were prepared by usinggravity and chill casting techniques. Zn-0.5Al alloy was subjected to hot rolling at 250 ºCand cold rolling at room temperature, while Zn-48Al alloy was also hot rolled at 250 ºC to20% reduction in the thickness of sample followed by partial remelting at 500 ºC. Severaltests were carried out such as physical, mechanical and chemical which include (XRF, XRD,OP, SEM, Microhardness (HV) and Tensile (cold, hot) test). Results showed that the"Zn-0.5Al alloy has poor mechanical properties and may not be regarded as a superplastic alloycompared with Zn-48Al alloy. The Zn-48Al alloy generally enhanced all properties. Themaximum elongation of (450%) was obtained in Zn-48Al alloy after thermomechanicalcontrolling process and partial remelting.

AEM Investigation of a Thermomechanically Processed U-6NB Alloy

1985 ◽  
Vol 43 ◽  
pp. 354-355
Author(s):  
Gail M. Ludtka
Keyword(s):  
Mechanical Properties ◽  
Solution Heat Treatment ◽  
Room Temperature ◽  
Thermomechanical Processing ◽  
High Yield ◽  
Ultrafine Grain ◽  
Superplastic Behavior ◽  
High Yield Strength ◽  
Ultrafine Grain Size ◽  
Before And After

The uranium-6 niobium (U-6Nb) alloy has been shown to exhibit elongations of 400-600% after a thermomechanical processing (TMP) sequence. This sequence (below the monotectoid temperature of 647°C) was utilized to develop the ultrafine grain size essential for superplastic behavior. The room temperature mechanical properties of the thermomechanically processed (TMP) U- 6Nb alloy before and after a gamma solution heat treatment (GSHT) were measured and compared to conventionally processed, GSHT U-6Nb alloy. These data are in Table I. The data show that the GSHT conditions have comparable mechanical properties and, so, the prior TMP treatment does not cause any loss of properties. However, the as-thermomechanically processed U-6Nb alloy exhibits negligible ductility and an extremely high yield strength. Metallography and AEM techniques have been utilized to characterize the TMP U- 6Nb microstructure to explain this behavior.

Microstructure and Mechanical Properties of Nanostructured Intermetallic Alloy Based on Ti2AlNb

2008 ◽  
Vol 584-586 ◽  
pp. 153-158
Author(s):  
M.R. Shagiev ◽  
G.A. Salishchev
Keyword(s):  
Mechanical Properties ◽  
Strain Rate ◽  
Room Temperature ◽  
Thermomechanical Processing ◽  
Nanocrystalline Structure ◽  
Nanostructured Material ◽  
Intermetallic Alloy ◽  
Superplastic Behavior ◽  
Average Grain Size ◽  
Rolling Temperatures

Homogeneous nanocrystalline structure with the average grain size of about 300 nm was produced in Ti2AlNb-based intermetallic alloy by a thermomechanical processing which included multistep isothermal forging at temperatures below the β-transus and intermediate annealings. Nanostructured material possessed excellent mechanical properties. At room temperature, elongations up to 25% were obtained and the ultimate strength reached 1400 MPa. The alloy exhibited superplastic behavior in the temperature range of 850-1000°C. The maximum elongation of 930% and steady state flow stress σ50 of about 125 MPa were obtained at 900°C and strain rate of 4.2×10-3 s-1. The rolling temperatures of nanostructured alloy were defined from analysis of its mechanical behavior at a typical rolling strain rate of about 10-1 s-1 and intermetallic sheets with improved mechanical properties were produced.

Effect of Small Addition of Si on Superplastic Elongation at Room Temperature in Zn-Al Eutectoid Superplastic Alloy

2014 ◽  
Vol 922 ◽  
pp. 328-331 ◽  
Author(s):  
Yuhei Kamiya ◽  
Masaki Ninomiya ◽  
Tokuteru Uesugi ◽  
Yorinobu Takigawa ◽  
Kenji Higashi
Keyword(s):  
Grain Size ◽  
Strain Rate ◽  
Room Temperature ◽  
Tensile Tests ◽  
Al Alloy ◽  
Superplastic Behavior ◽  
Superplastic Alloy ◽  
Average Grain Size ◽  
Before And After ◽  
Si Content

Recent experimental data have revealed that a small amount of impurity can significantly influence the superplastic behavior in Zn-Al eutectoid superplastic alloy. However, the effect of Si content on the superplastic behavior in Zn-Al alloy has not been reported. In this study, the superplastic behavior at a room temperature of two grades of the Zn-Al eutectoid superplastic alloy was studied under identical conditions of grain size, temperature, and strain rate. These two grades were prepared from high-purity Zn, Al and Al-Si alloy using the same procedure but different Si impurity levels; Zn-Al-10Si and Zn-Al-1000Si contain 10 and 900 wt. ppm of Si, respectively. As a result of annealing treatments, an average grain size of 0.6 μm in both grades. To investigate the effects of Si content on superplastic properties, the tensile tests were performed at a room temperature of 298 K and a constant strain rate of 1×10-3 s-1. Microstructures before and after the tensile tests was observed using a scanning electron microscope. The experimental results show that the elongations decreased with increasing the Si content. In contrast, the flow stress of Zn-Al alloys was not affected by the Si content. On the microstructure observation of the two grades of the Zn-Al alloy before and after the tensile tests, cavities existed at grain boundaries and strain enhanced grain growth was observed.

Microstructure and Mechanical Properties of Ni3Al-Ai2O3 Composites Produced by Hot Extrusion

1990 ◽  
Vol 194 ◽  
Author(s):  
C. G. McKamey ◽  
E. H. Lee
Keyword(s):  
Room Temperature ◽  
Hot Extrusion ◽  
Tensile Tests ◽  
Grain Boundary Sliding ◽  
Diffusional Creep ◽  
Superplastic Behavior ◽  
Fine Grain ◽  
Boundary Sliding ◽  
Microstructural Studies ◽  
Better Than

AbstractHot extrusion of premixed charges of 10–20 vol% chopped A12O fiber and Ni3Al powder has resulted in composite alloys of near theoretical density. In tensile tests at room temperature, density-compensated yield strengths of some of these composite alloys are as good or better than those of as-cast Ni3Al without reinforcement; however strengths at 1000°C in vacuum are lower. The low strength at 1000°C and fine grain size (2–3/μm) suggest the presence of superplastic behavior and the accompanying diffusional creep and grain boundary sliding. This presentation discusses our findings to date and includes microstructural studies and tensile properties, both at room temperature in air and 1000°C in vacuum.

Improved Mechanical Properties of Ti2AlNb-Based Intermetallic Alloys and Composites

2008 ◽  
Vol 59 ◽  
pp. 105-108 ◽  
Author(s):  
M.R. Shagiev ◽  
R.M. Galeyev ◽  
Oleg R. Valiakhmetov ◽  
Rinat V. Safiullin
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Composite Plates ◽  
Nanostructured Material ◽  
Intermetallic Alloys ◽  
Steady State Flow ◽  
Superplastic Behavior ◽  
Homogeneous Microstructure ◽  
Average Grain Size

Mechanical properties of a Ti2AlNb-based intermetallic alloy both at room and elevated temperatures were considerably improved due to formation of a homogeneous microstructure with the average grain size of about 300 nm. At room temperature, elongations up to 25% were obtained and the ultimate strength reached 1400 MPa. The alloy exhibited superplastic behavior in the temperature range of 850-1000°C. The maximum elongation of 930% and steady state flow stress 50 of about 125 MPa were obtained at 900°C and strain rate of 4.210-3 s-1. The nanostructured material was used for production of intermetallic sheets and multilayer composite plates consisting of alternating layers of orthorhombic intermetallic and commercial high temperature titanium alloy. Ti2AlNb-based sheets and composites exhibited improved mechanical properties.

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