Superplastic Properties of Ultrafine-Grained Allvac 718Plus Alloy Processed by Multiple Forging

2014 ◽  
pp. 145-153
Author(s):  
Shamil Mukhtarov ◽  
Valery Imayev
Keyword(s):  
Ultrafine Grained ◽  
Superplastic Properties

Superplastic Behavior of Friction-Stir Welded Joints of an Al-Mg-Sc Alloy with Ultrafine-Grained Microstructure

2016 ◽  
Vol 838-839 ◽  
pp. 338-343 ◽  
Author(s):  
Sergey Malopheyev ◽  
Sergey Mironov ◽  
Igor Vysotskiy ◽  
Rustam Kaibyshev
Keyword(s):  
Strain Rate ◽  
True Strain ◽  
Rate Sensitivity ◽  
Initial Strain Rate ◽  
Sensitivity Coefficient ◽  
Friction Stir ◽  
Angular Pressing ◽  
Ultrafine Grained ◽  
Elongation To Failure ◽  
Superplastic Properties

The commercial Al-5.4Mg-0.2Sc-0.1Zr alloy was subjected to equal-channel angular pressing at 300°C to a true strain ~12 followed by cold rolling to a total thickness reduction of 80%. The ultrafine-grained sheets were joined by friction stir welding (FSW). To evaluate superplastic properties of the weldments, the tensile samples including all of the characteristic FSW microstructural zones were machined perpendicular to the welding direction and pulled up to failure in the temperature range of 400 to 500°C and at strain rates of 2.8×10-4 s-1 to 5.6×10-1 s-1. The friction-stir welded material exhibited excellent superplastic properties. The highest elongation-to-failure of ~1370% was recorded at a temperature of ~450°C and an initial strain rate of 5.6×10-2 s-1, where the strain rate sensitivity coefficient was about 0.64. The relationship between superplastic ductility and microstructure is discussed.

Effect of Rolling on Superplastic Behavior of an Al-Mg-Sc Alloy with Ultrafine-Grained Structure

2016 ◽  
Vol 838-839 ◽  
pp. 416-421 ◽  
Author(s):  
Andrii Dubyna ◽  
Sergey Malopheyev ◽  
Rustam Kaibyshev
Keyword(s):  
Cold Rolling ◽  
Strain Rate ◽  
Rolling Direction ◽  
Initial Strain Rate ◽  
Warm Rolling ◽  
Initial Strain ◽  
Superplastic Behavior ◽  
Ultrafine Grained ◽  
Elongation To Failure ◽  
Superplastic Properties

The superplastic behavior of a commercial aluminum alloy denoted as 1570 Al with a chemical composition of Al-6%Mg-0.5%Mn-0.2%Sc-0.07%Zr (in wt. %) and ultrafine-grained (UFG) structure produced by equal channel angular pressing at 300°C to a true strain ~12 was studied after final cold or warm rolling. The tensile specimens were machined along rolling direction and pulled up to failure in the temperature range of 250 to 500°C at strain rates ranging from 10-4 s-1 to 10-1 s-1. The specimens produced by warm or cold rolling exhibit different superplastic behavior. The material subjected to warm rolling exhibits excellent superplastic properties; the highest elongation-to-failure of ~1970% was recorded at a temperature of ~450°C and an initial strain rate of 1.4×10-1 s-1. On the other hand, the material subjected to cold rolling demonstrates moderate superplastic properties; the highest elongation-to-failure of ~755% appears at a temperature of ~300°C and an initial strain rate of 1.4×10-2 s-1.

scholarly journals Dynamic Recrystallization and Grain Growth in a ZK60 Magnesium Alloy Sheet Produced by Isothermal Rolling

2004 ◽  
Vol 467-470 ◽  
pp. 1175-1180 ◽  
Author(s):  
Arthur Galiyev ◽  
Rustam Kaibyshev
Keyword(s):  
Magnesium Alloy ◽  
Dynamic Recrystallization ◽  
Grain Refinement ◽  
Grain Growth ◽  
Alloy Sheet ◽  
Ultrafine Grained ◽  
Zk60 Alloy ◽  
Higher Temperature ◽  
Superplastic Properties ◽  
Zk60 Magnesium Alloy

A ZK60 magnesium alloy was subjected to isothermal rolling (IR) at 275 and 300°C. This processing resulted in grain refinement through dynamic recrystallization (DRX) at both temperatures. The recrystallized volume fractions of 82 and 95% and average sizes of fine grains of 2.5 and 3.7 µm were achieved after IR at 275 and 300°C, respectively. It was shown that the ultrafine-grained structure produced by DRX at 300°C exhibited higher stability under following static and dynamic annealing than that produced at 275°C. This fact was attributed with the formation of a less constrained DRX structure at higher temperature of IR. As a result, the sheet produced from the ZK60 alloy at 300°C showed superior superplastic properties. Conversely, it was not feasible to enhance the superplastic properties in the ultrafine-grained alloy produced at 275°C because significant grain growth occurred during further processing of the as-rolled alloy.

An Examination of the Deformation Process in Equal-Channel Angular Pressing

1999 ◽  
Vol 601 ◽  
Author(s):  
Patrick B. Berbon ◽  
Minoru Furukawa ◽  
Zenji Horita ◽  
Minoru Nemoto ◽  
Terence G. Langdon
Keyword(s):  
Low Temperatures ◽  
Materials Science ◽  
Physical And Mechanical Properties ◽  
New Techniques ◽  
Angular Pressing ◽  
Ultrafine Grained ◽  
Ultrafine Grained Materials ◽  
Superplastic Properties ◽  
Bulk Processing ◽  
Microcrystalline Materials

AbstractIn the past decade, there has been an important emphasis in materials science on the production and use of ultrafine-grained materials. These materials offer wide-ranging advantages such as an improvement in strength at low temperatures and enhanced superplastic behavior at high temperatures. New techniques to process these materials have been developed. Good properties have been achieved by powder metallurgy and by techniques of bulk processing. Equal-channel angular (ECA) pressing is a bulkprocessing technique which has led to some remarkable achievements in the production of sub-microcrystalline materials with excellent superplastic properties at low temperatures and high strain rates. When considering the currently available physical and mechanical properties of these materials, it appears that some aspects cannot be explained solely by the very small grain size. In fact, the specific mode of deformation occurring in ECA pressing appears to have an influence on the final properties. This paper reviews the details of this metal working technique and then provides an explanation for the observed microstructures, their thermal stability and their remarkable superplastic properties.

Superplastic Properties of Ultrafine-Grained Mg Alloys Processed by Extrusion Plus Equal-Channel Angular Pressing

2003 ◽  
Vol 419-422 ◽  
pp. 551-556 ◽  
Author(s):  
Yuichi Miyahara ◽  
Kiyoshi Matsubara ◽  
Koji Neishi ◽  
Z. Horita ◽  
Terence G. Langdon
Keyword(s):  
Equal Channel Angular Pressing ◽  
Mg Alloys ◽  
Angular Pressing ◽  
Ultrafine Grained ◽  
Superplastic Properties

Low-Temperature Superplasticity of the Ni-Based EK61 Superalloy and Application of this Effect to Obtain Sound Solid Phase Joints

2018 ◽  
Vol 385 ◽  
pp. 150-154 ◽  
Author(s):  
Elvina Galieva ◽  
Vener Valitov ◽  
Ramil Lutfullin ◽  
Aerika Bikmukhametova
Keyword(s):  
Low Temperature ◽  
Strain Rate ◽  
Solid Phase ◽  
Rate Sensitivity ◽  
Strain Rate Range ◽  
Sensitivity Factor ◽  
Temperature Range ◽  
Ultrafine Grained ◽  
Nickel Based Alloy ◽  
Superplastic Properties

It is shown that formation of ultrafine-grained structure in EK61 superalloy up to grain sizes less than 1 μm provides to realize superplastic properties. The influence of deformation in the temperature range 600-1100 °C and strain rate range 10-4s-1– 10-3s-1on the microstructure and properties of ultrafine-grained nickel-based alloy EK61 is studied. It is established that in temperature range 750-900 °C the alloy demonstrates superplasticity (SP) characteristics: strain rate sensitivity factor “m” correspond to 0.39-0.59, stable structure and low changes in the form and size of grains. The maximum SP is displayed at temperatures of 800 °C, wherein the elongation is 1431 %. It has been experimentally confirmed that the use of low-temperature superplasticity is a promising for processing sound solid phase joints by pressure welding of similar and dissimilar Ni-based superalloys.

Superplastic Behavior of ATI 718Plus Superalloy

2016 ◽  
Vol 838-839 ◽  
pp. 557-562 ◽  
Author(s):  
Shamil Kh. Mukhtarov ◽  
Farid Z. Utyashev
Keyword(s):  
Strain Rate ◽  
Temperature Interval ◽  
Superplastic Forming ◽  
Low Flow ◽  
Superplastic Behavior ◽  
Fine Grained ◽  
Working Temperature ◽  
Ultrafine Grained ◽  
Thin Walled ◽  
Superplastic Properties

Complex shaped, ultra thin-walled parts can be manufactured using superplastic forming. Hot working temperature for the production of fine-grained billets (d=5-15 μm) out of ATI Allvac 718Plus® superalloy is in the range of 982-1038°C. An ultrafine-grained structure (d=0.3 μm) was produced by multi-axial forging with a gradual decrease of the forging temperature from 950 to 700°C. Superplastic properties of the alloy were carried out in the temperature interval of 700-950°C. It has been revealed that the fine-grained alloy provided superplastic elongations about 300% at 950°C and strain rate of 10-4 s-1. The highest elongation of ultrafine-grained alloy was about 1450% and very low flow stresses were reached at 900°C and strain rate of 3×10-4 s-1. The ultrafine-grained alloy showed superplastic properties also at 700°C (0.62Tm). The microstructure and superplastic properties of the alloys 718 and 718Plus are compared.

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