scholarly journals Evolution of microstructure and twin density during thermomechanical processing in a γ-γ’ nickel-based superalloy

2012 ◽  
Vol 60 (13-14) ◽  
pp. 5056-5066 ◽  
Author(s):  
N. Bozzolo ◽  
N. Souaï ◽  
R.E. Logé
Keyword(s):  
Thermomechanical Processing ◽  
Twin Density ◽  
Nickel Based Superalloy ◽  
Evolution Of Microstructure

Metallography of Aluminum Alloys: Atlas of Microstructures

2019 ◽  
Author(s):  
S.V.S. Narayana Murty ◽  
Sushant K. Manwatkar ◽  
P. Ramesh Narayanan
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloys ◽  
Microstructural Evolution ◽  
Electron Micrographs ◽  
Thermomechanical Processing ◽  
Alloy System ◽  
Scanning Electron Micrographs ◽  
Cast Aluminum Alloys ◽  
Transmission Electron ◽  
Evolution Of Microstructure

Microstructure plays an important role in obtaining the desired properties in metallic materials in general and aluminum alloys in particular. Mechanical properties of aluminum alloys can be significantly altered by changing the microstructure. No other alloy system can boast of as many temper conditions as aluminum alloys. With the progress in the understanding of microstructure–mechanical property relationships in these materials, “tailor made” alloys to meet specific demands are being industrially developed. The broad spectrum of aluminum alloys in wide range of temper conditions offer materials with widely varying mechanical properties for structural designers. In order to select aluminum alloys with the desired properties for the intended application, it is essential to understand the role of microstructure under actual service conditions. It is in this context “Metallography of aluminum alloys” becomes very important. This chapter provides an insight in to the microstructural evolution of aluminum alloys from the as-cast condition to the final product. Typical examples of microstructural evolution in different aluminum alloys under various thermomechanical conditions are presented here. An atlas of microstructures of commercial and experimental wrought and cast aluminum alloys is presented in an appendix to this book. This appendix includes optical photomicrographs of both cast and wrought alloys and scanning electron micrographs of polished surfaces as well as fracture surfaces of various aluminum alloys as well as transmission electron micrographs as separate annexure. Readers are encouraged to go through the optical microstructures and fractographs along with this chapter for better understanding of the evolution of microstructure as a function of alloying additions, thermomechanical processing conditions, and fracture behavior under tension.

scholarly journals Taguchi Design for Heat Treatment of Rene 65 Components

2019 ◽  
Author(s):  
Christina Maria Katsari ◽  
Stephen Yue ◽  
Andrew Wessman
Keyword(s):  
Heat Treatment ◽  
Volume Fraction ◽  
Thermomechanical Processing ◽  
Hold Time ◽  
Turbine Blades ◽  
High Strength ◽  
Gamma Prime ◽  
Nickel Based Superalloy ◽  
Hold Temperature ◽  
Microhardness Testing

Abstract Rene 65 is a nickel-based superalloy used in aerospace components such as turbine blades and disks. The microstructure in the as received condition of the superalloy consists of ~40% volume fraction of gamma prime precipitates, which gives such a high strength that thermomechanical processing is problematic. The goal of this study was to develop a heat treatment for manufacturing of Rene 65 components by changing the size distribution and volume fraction of those precipitates and lowering the strength. Gamma prime in this alloy is observed in three sizes, ranging from a few μm to tens of nm. For the design of the heat treatments, Design of Experiments (DOE) has been used; more specifically Taguchi’s L8 matrix. The four factors that are examined are cooling rate, hold temperature, hold time and cooling method to room temperature. The levels of the factors were two (high and low) with replication. Microstructures were characterized by Scanning Electron Microscopy and mechanical properties by Vickers microhardness testing.

Evolution of microstructure in a nickel-based superalloy as a function of ageing time

2011 ◽  
Vol 91 (7) ◽  
pp. 483-490 ◽  
Author(s):  
E-Wen Huang ◽  
Yun Liu ◽  
Yang Ren ◽  
Lionel Porcar ◽  
Ji-Jung Kai ◽  
...  
Keyword(s):  
Ageing Time ◽  
Nickel Based Superalloy ◽  
Evolution Of Microstructure

Characteristics of the GBS – SDC Transition during Bi-Axial Forming of AA5083

2012 ◽  
Vol 735 ◽  
pp. 43-48 ◽  
Author(s):  
Terry McNelley ◽  
Keiichiro Oh Ishi ◽  
Srinivasan Swaminathan ◽  
John Bradley ◽  
Paul Krajewski ◽  
...  
Keyword(s):  
Cold Working ◽  
Thermomechanical Processing ◽  
Rolling Texture ◽  
Solute Drag ◽  
Grain Boundary Sliding ◽  
Subsequent Evolution ◽  
Refined Grains ◽  
Boundary Sliding ◽  
Evolution Of Microstructure ◽  
Solute Drag Creep

Thermomechanical processing to enable superplasticity in AA5083 materials includes cold working followed by heating prior to hot blow forming. Upon heating for forming at 450°C, a B-type ({110}) rolling texture is replaced by a near-random texture with a weak superimposed cube orientation parallel to the sheet normal. The presence of refined grains 7 – 8μm in size reflects the predominance of particle-stimulated nucleation of recrystallization prior to forming. The subsequent evolution of microstructure, texture and cavitation behaviour during biaxial deformation in the solute drag creep (SDC) and grain boundary sliding (GBS) regimes will be presented.

scholarly journals The Influence of Thermomechanical Processing Conditions on the Evolution of Microstructure and Crystallographic Textures and the Mechanical Properties of Deformed Mild Steels in the Intercritical Region

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Mandana Zebarjadi Sar ◽  
Silvia Barella ◽  
Andrea Gruttadauria ◽  
Davide Mombelli ◽  
Carlo Mapelli
Keyword(s):  
Mechanical Properties ◽  
Strain Aging ◽  
Thermomechanical Processing ◽  
Tensile Tests ◽  
Optical Microscope ◽  
Warm Rolling ◽  
Consequent Reduction ◽  
Intercritical Region ◽  
Evolution Of Microstructure

Rolling temperature and rolling reduction intensively influence the formation of Luder lines and fluting marks in mild steels. They govern these effects through control of strain aging. In order to enhance the strain aging resistance and the consequent reduction of yield point elongation and fluting intensity, warm rolling without using the skin pass process is applied. The development of microstructure and crystallographic textures during deformation process and the determination of fluting intensity and mechanical properties consisting of tensile and formability properties in terms of different thermomechanical conditions (RT and RR%) were investigated in this study. These properties are determined through the use of bending, tensile tests, optical microscope, and EBSD analysis.

scholarly journals Evolution of the Annealing Twin Density during δ-Supersolvus Grain Growth in the Nickel-Based Superalloy Inconel™ 718

Metals ◽  
2015 ◽  
Vol 6 (1) ◽  
pp. 5 ◽  
Author(s):  
Yuan Jin ◽  
Marc Bernacki ◽  
Andrea Agnoli ◽  
Brian Lin ◽  
Gregory Rohrer ◽  
...  
Keyword(s):  
Grain Growth ◽  
Annealing Twin ◽  
Twin Density ◽  
Nickel Based Superalloy

Processing Effects on the Microstructure and Properties of Fe-Based Superelastic Alloys

2018 ◽  
Author(s):  
Mihai Popa ◽  
Elena Mihalache ◽  
Vasile Danut Cojocaru ◽  
Carmela Gurău ◽  
Gheorghe Gurău ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermomechanical Processing ◽  
Solution Treatment ◽  
Micro Hardness ◽  
Cyclic Heat Treatment ◽  
Spark Erosion ◽  
Cyclic Heat ◽  
Processing Effects ◽  
Evolution Of Microstructure ◽  
Processing Steps

This study focuses on the evolution of microstructure and mechanical properties following thermomechanical processing of FeMnAlNi superelastic alloys. For Fe43.5Mn34Al15Ni7.5, which is an eligible candidate for superelastic applications, the effects of substituting ± 1.5 at. % Al with Ni were analyzed. The ingots were subjected to five thermomechanical processing steps: (i) hot rolling; (ii) annealing; (iii) cold rolling; (iv) cyclic heat treatment under protective Ar atmosphere and (v) solution treatment and ageing. The evolution of microstructure following the five processing steps was monitored by optical and scanning electron microscopy and energy dispersive spectroscopy. Micro-hardness evolution was monitored during consecutive processing steps. Tensile specimens were cut by spark erosion and mechanical properties were evaluated following consecutive processing steps taking into account the microstructural evolution.

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