Nanotechnology Now





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > What makes superalloys super - hierarchical microstructure of a superalloy

The image shows the three-dimensional reconstruction of an atom probe measurement. The γ matrix (purple) can be seen surrounding the cuboidal γ’ precipitates (green). Only a few nanometre-sized γ platelets can be seen in the γ’ precipitates. Atom probe tomography allows a site specific analysis of the structure at the atomic scale and reveals the chemical composition in measurements of individual areas. Image: HZB
The image shows the three-dimensional reconstruction of an atom probe measurement. The γ matrix (purple) can be seen surrounding the cuboidal γ’ precipitates (green). Only a few nanometre-sized γ platelets can be seen in the γ’ precipitates. Atom probe tomography allows a site specific analysis of the structure at the atomic scale and reveals the chemical composition in measurements of individual areas.

Image: HZB

Abstract:
Researchers have observed for the first time in detail how a hierarchical microstructure develops during heat treatment of a superalloy

What makes superalloys super - hierarchical microstructure of a superalloy

Berlin, Germany | Posted on January 14th, 2014

Materials in high-performance turbines have to withstand not only powerful mechanical forces, they also have to maintain their chemical and mechanical properties almost up to their melting points. For this reason, turbine manufacturers have employed special nickel-based high-performance alloys for decades. New work from Helmholtz-Zentrum Berlin für Materialien and Energie (HZB) now shows in detail how new phases in a nickel-based alloy form and evolve, providing clues to how high-performance alloys could be improved. Doctoral student Florian Vogel and Dr. Nelia Wanderka from the HZB Institute of Applied Materials have elegantly combined two methods to accomplish this: transmission electron microscopy (TEM) and atom probe tomography (APT), which they carried out in collaboration with colleagues from the University of Münster.

They were interested in a phase separation phenomenon that has been known for around 50 years, but could neither be precisely observed nor understood until now: The microstructure of nickel-based alloys changes under controlled ageing or heat treatment and in the classical two-phase microstructure new phases are initially formed. Wanderka and Vogel were able to precisely observe the phase separation process on the atomic scale for the first time.

To do so, they simulated the ageing process of the alloy by heat treating it for different periods. They documented how the microstructure changed during the ageing of the alloy using micrographs from the transmission electron microscope. Whereas the classical two-phase microstructure consists of cuboid γ' precipitates embedded in a so called γ-matrix, during heat treatment, spherical γ particles initially form in the γ' precipitates of the alloy, then further coalesce into plates that finally split the γ' precipitates. The thermo-mechanical properties of these types of alloys depend largely on the stability of this γ/γ´ microstructure.

In order to determine the atomic constituents of the individual phases, but primarily to learn about the formation and make-up of the poorly understood γ particle, Vogel and Wanderka investigated the aged samples using atom probe tomography at the University of Münster. They succeeded in reconstructing the atomic lattice of the samples layer by layer and determining the composition of all phases, so that they could explain the chemical evolution of the γ particles.

"Until now, it was assumed that splitting of the γ' precipitates refines the microstructure during ageing, which would be beneficial for the alloy's stability under thermo-mechanical load. We were able to show that this is not correct. The microstructure indeed changes considerably, but it is not improved by the splitting however. We were actually able to correlate the best mechanical properties with the presence of spherical or plate-like γ particles and not with the later stages after splitting of the γ' precipitates has taken place", explains Florian Vogel. Nelia Wanderka adds: "If we want to improve the stability of the microstructure and thus the thermomechanical properties of the alloy, we need to be sure that the γ' precipitates are not split by the γ particles, but instead remain intact through appropriate heat treatment and composition of the alloy. Atom probe tomography helps us in understanding the role of the alloying elements in the formation and growth of the γ particles. From this, we can learn how to influence these processes."

####

For more information, please click here

Contacts:
Dr. Nelia Wanderka

49-308-062-42079

Florian Vogel
Tel (030) 8062 - 43217
Fax (030) 8062 - 43059


Dr. Antonia Rötger
Tel (030) 8062 - 43733
Fax (030) 8062 - 42998

Copyright © Helmholtz-Zentrum Berlin für Materialien und Energie

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

The work was published 20 Dec 2013 in the distinguished journal Nature Communications. doi:10.1038/ncomms3955:

Related News Press

Imaging

How Graphene–based Nanomaterials and Films Revolutionize Science Explained in July 9 Webinar Hosted by Park Systems June 29th, 2015

Keysight Technologies Introduces Ultrafast-Scanning 9500 Atomic Force Microscope: New Integrated Software, Hardware Delivers Unmatched Scan Rates June 29th, 2015

Rice University boots up powerful microscopes: New electron microscopes will capture images at subnanometer resolution June 29th, 2015

News and information

The Hydrogen-Fuel cell will revolutionize the economy of the world: New non-platinum and nanosized catalyst for polymer electrolyte fuel cell June 29th, 2015

June 29th, 2015

Efforts to Use Smart Nanocarriers to Cure Leukemia Yield Promising Results June 29th, 2015

Making new materials with micro-explosions: ANU media release: Scientists have made exotic new materials by creating laser-induced micro-explosions in silicon, the common computer chip material June 29th, 2015

Discoveries

The Hydrogen-Fuel cell will revolutionize the economy of the world: New non-platinum and nanosized catalyst for polymer electrolyte fuel cell June 29th, 2015

June 29th, 2015

Efforts to Use Smart Nanocarriers to Cure Leukemia Yield Promising Results June 29th, 2015

Making new materials with micro-explosions: ANU media release: Scientists have made exotic new materials by creating laser-induced micro-explosions in silicon, the common computer chip material June 29th, 2015

Materials/Metamaterials

Green Chemistry Methods Used in Iran to Produce Zinc Oxide Nanoparticles June 27th, 2015

Spain nanotechnology featured at NANO KOREA 2015 June 26th, 2015

Dais Analytic Unveils New Version of Aqualyte Membrane Technology: Updates to the Basis of the Company's Industry-Changing Nanotechnology Designed to Strengthen Position in Global Air, Energy, and Water Markets June 26th, 2015

Iranian Researchers Synthesize Nanostructures with Controlled Shape, Structure June 25th, 2015

Announcements

The Hydrogen-Fuel cell will revolutionize the economy of the world: New non-platinum and nanosized catalyst for polymer electrolyte fuel cell June 29th, 2015

June 29th, 2015

Efforts to Use Smart Nanocarriers to Cure Leukemia Yield Promising Results June 29th, 2015

Making new materials with micro-explosions: ANU media release: Scientists have made exotic new materials by creating laser-induced micro-explosions in silicon, the common computer chip material June 29th, 2015

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers

June 29th, 2015

Efforts to Use Smart Nanocarriers to Cure Leukemia Yield Promising Results June 29th, 2015

Making new materials with micro-explosions: ANU media release: Scientists have made exotic new materials by creating laser-induced micro-explosions in silicon, the common computer chip material June 29th, 2015

Helium 'balloons' offer new path to control complex materials June 27th, 2015

Tools

How Graphene–based Nanomaterials and Films Revolutionize Science Explained in July 9 Webinar Hosted by Park Systems June 29th, 2015

Keysight Technologies Introduces Ultrafast-Scanning 9500 Atomic Force Microscope: New Integrated Software, Hardware Delivers Unmatched Scan Rates June 29th, 2015

Rice University boots up powerful microscopes: New electron microscopes will capture images at subnanometer resolution June 29th, 2015

X-rays and electrons join forces to map catalytic reactions in real-time: New technique combines electron microscopy and synchrotron X-rays to track chemical reactions under real operating conditions June 29th, 2015

Automotive/Transportation

June 29th, 2015

Buckle up for fast ionic conduction June 16th, 2015

A protective shield for sensitive catalysts: Hydrogels block harmful oxygen June 15th, 2015

Slip sliding away: Graphene and diamonds prove a slippery combination June 10th, 2015

Aerospace/Space

Discovery paves way for new kinds of superconducting electronics June 22nd, 2015

Deben reports on how the University of Portsmouth use in situ µXCT compressive testing to help answer how materials respond to complex loading conditions June 17th, 2015

Slip sliding away: Graphene and diamonds prove a slippery combination June 10th, 2015

Ultrafast heat conduction can manipulate nanoscale magnets June 8th, 2015

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More










ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project