The process of thixoforming, which has been part of many researches during the last decades, combines the advantages of forging and casting for the shaping of metallic components. But due to the high temperatures of semi-solid steel alloys high demands on the tools are requested. To resists the thermal and mechanical loads (wear, friction, thermal and thermomechanical fatigue) protecting thin films are necessary. In this regard crystalline gamma-Al2O3 deposited via Physical Vapour Deposition (PVD) is a promising candidate: It exhibits high thermal stability, high oxidation resistance and high hot hardness. In the present work the application of a (Ti, Al)N/gamma-Al2O3 coating deposited by means of Magnetron Sputter Ion Plating in an industrial coating unit is presented. The coating was analysed by means of Rockwell test, nanoindentation, and Scanning Electron Microscopy (SEM). The coated tool was tested in thixoforging experiments with steel grade X210CrW12 (AlSI D6). The surface of the coated dies was examined with Scanning Electron Microscope (SEM) after 22, 42, 90 and 170 forging cycles.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1166/jnn.2011.3469 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Exploring the Crystal Structure and Electronic Properties of γ-AlO: Machine Learning Drives Future Material Innovations.
ACS Appl Mater Interfaces
November 2024
State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
Article Synopsis
- Researchers face challenges in determining the crystal structure of γ-AlO due to atomic disorder and purity issues, but this study employs machine learning and density functional theory (DFT) to advance the understanding.
- A potential supercell structure was identified and confirmed through advanced microscopy techniques, revealing that γ-AlO deviates from a typical spinel structure, with octahedral vacancies playing a role in energy reduction.
- Under an external electric field, significant changes in the material's band structure result in a narrowing bandgap and increased metallic behavior, which helps explain variations in electrical conductivity and provides insights into the dielectric breakdown of insulating materials.
Chemical and Structural Characterization of Amorphous and Crystalline Alumina Obtained by Alternative Sol-Gel Preparation Routes.
Materials (Basel)
April 2021
Faculty of Material Science and Ceramics, AGH University of Science and Technology, 30-059 Krakow, Poland.
Aluminum oxide is one of the most commonly used materials in the industry. It is used in the field of catalysis, refractories, and optics. Despite the fact that there are many techniques available, there is still a great challenge in obtaining a material with desired and designed properties.
View Article and Find Full Text PDFEffect of Duty Cycle on Properties of Al₂O₃ Ceramic Coatings Fabricated on TiAl Alloy via Cathodic Plasma Electrolytic Deposition.
Materials (Basel)
October 2018
School of Aeronautics, Northwestern Polytechnical University, Xi'an 710072, China.
In order to study the effect of duty cycle during the cathodic plasma electrolytic deposition (CPED) process, Al₂O₃ ceramic coatings were fabricated via the CPED technique on prepared TiAl alloy in an Al(NO₃)₃ electrolyte with different duty cycles. Microstructure, morphology, and chemical compositions of coatings were analyzed by scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The mechanical properties, such as thickness, hardness, and binding strength, were also characterized, and heat-resistance and wear-resistance tested.
View Article and Find Full Text PDFThe Mechanism of Low-Temperature Oxidation of Carbon Monoxide by Oxygen over the PdCl₂-CuCl₂/γ-Al₂O₃ Nanocatalyst.
Nanomaterials (Basel)
April 2018
Moscow Technological University, Institute of Fine Chemical Technology, Department of General Chemical Technology, Moscow 119571, Russia.
The state of palladium and copper on the surface of the PdCl₂-CuCl₂/γ-Al₂O₃ nanocatalyst for the low-temperature oxidation of CO by molecular oxygen was studied by various spectroscopic techniques. Using X-ray absorption spectroscopy (XAS), powder X-ray diffraction (XRD), and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), freshly prepared samples of the catalyst were studied. The same samples were also evaluated after interaction with CO, O₂, and H₂O vapor in various combinations.
View Article and Find Full Text PDFNano-alumina powders/ceramics derived from aluminum foil waste at low temperature for various industrial applications.
J Environ Manage
December 2016
Chemistry Department, Faculty of Science, Cairo University, Giza, Egypt.
In this work, nanoscale single crystalline γ- and α-alumina powders have been successfully prepared from aluminum foil waste precursor via co-precipitation method using NH4OH as a precipitant. The obtained gel after co-precipitation treatment, was calcined at different temperatures (500,700, 900, 1050, 1100, 1300 and 1500 °C) and the products were characterized by XRD, FTIR and HRTEM. The results revealed that nano-γ-Al2O3 was fully transformed to nanometer-sized α-Al2O3 (36-200 nm) after annealing at temperatures as low as 1100 °C.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!