Aluminum Alloys, Processing and Characterization: Characterization
Sponsored by: TMS Light Metals Division, TMS: Aluminum Committee
Program Organizers: Yanjun Li, Norwegian University of Science and Technology
Wednesday 2:00 PM
March 1, 2017
Location: San Diego Convention Ctr
Session Chair: Tongguang Zhai, University of Kentucky
2:00 PM Introductory Comments
Algorithm for Finding the Correlation between the Properties of Wrought Aluminum Alloys, the Chemical Composition and the Processing Parameters: Varužan Kevorkijan1; Branko Hmelak2; Peter Cvahte3; Sara Hmelak2; Vukašin Dragojević4; Uroš Kovačec5; Marina Jelen5; Darja Volšak6; 1Impol R in R d.o.o.; 2Alcad d.o.o.; 3Impol 2000 d.d.; 4Impol PCP d.o.o.; 5Impol LLT d.o.o.; 6Impol FT d.o.o.
The successful industrial modeling of wrought aluminum alloys with the desired combination of properties is based on finding the surjective and inverse correlation T(C, PP) ↔ P between the properties, P, of the final product and the different technological paths T(C, PP) capable of providing it (and vice-versa). Here, C represents the chemical composition of the alloy and PP is the processing parameters. The algorithm presented in this work is based on the functional equivalency of two different technological paths, T1 and T2, able to provide the same combination of properties, written as P(T1) = P(T2), where P(T1) and P(T2) represent the properties obtained using the various paths T1 and T2 in vector space. The selection of the best among the functionally equivalent technological paths, T, was performed by applying the minimum-cost criterion. The cognitive computing of the real data confirmed the promising industrial potential of such a modeling for high-strength and recycling-friendly wrought aluminum alloys.
Analysis of an Aluminium Alloy Containing Trace Elements: Christian Simensen1; Stephan Kubowicz1; Bĝrge Holme1; Joachim Greff1; 1SINTEF
The microstructure of an Al-Si-Mn-Fe alloy was determined using SEM and Tof-SIMS. The trace elements detected were chlorides and some fluorides. Potassium was found in large cracks along boundaries. Sn-rods were found on the surface of α-Al(Mn,Fe)Si-particles, on grain boundaries and as separate particles. Small Pb-Sn particles were detected close to grain boundaries. α-Al(Mn,Fe)Si-particles were 1-5 μm in size and gave pronounced Mn- and Fe-peaks in Tof-SIMS, while silicon did not. SEM-analysis showed that the phase had the composition (wt%): 59Al-12.2Si-17Mn-11.9Fe. Separate analyses of matrix and these particles showed that the particles were sputtered at a slower rate than the matrix, and the sensitivity factor (Sx/Al) was lower in the particles as compared matrix. These observations were explained by the fact that intermetallic phases are substantially harder that Al-matrix, and that the Si-atoms and a fraction of the Mn and Fe atoms are covalently bonded in α-Al(Mn,Fe)Si-particles.
Determination of Aluminum Oxide Thickness on the Annealed Surface of 8000 Series Aluminum Foil by Fourier Transform Infrared Spectroscopy: Onur Birbasar1; Özlem Uçar1; Ayten Mese2; Durmuş Özdemir2; Murat Dündar1; 1Assan Alüminyum; 2İzmir Institute Of Technology
Aluminium foil produced with prescribed thermomechanical processing route develop oxide film. Alloy chemistry and annealing practices, particularly its duration and exposed temperature, determine the characteristics of the oxide film. The magnitude and characteristics of the oxide film may impair surface features leading to serious problems in some applications, such as coating, printing and in some severe cases failure in formability. Therefore, it is important for the rolling industry to be able to monitor the oxide formation on the foil products and quantify its thickness. Well known methods to measure an oxide thickness that is in the order of nanometer, require meticulous sample preparation techniques, long duration for measurements and sophisticated equipment. However, in this study, a simple and rapid grazing angle attenuated total reflectance infrared spectroscopic method combined with chemometrics multivariate calibration has been developed for the oxide thickness determination which is validated with x-ray photoelectron spectroscopy (XPS).
Using Guard Bands to Accommodate Uncertainty in the Spark AES Analysis of Aluminum or Aluminum Alloys When Determining Compliance with Specified Composition Limits: John Weritz1; Denis Choquette2; Thomas Belliveau3; Rebecca Wyss4; Michael Ruschak4; Albert Wills5; Olivier Gabis6; John Sieber7; 1The Aluminum Association; 2Rio Tinto; 3Novelis; 4Alcoa, Inc.; 5Sapa Industrial Extrusions; 6Wagstaff Inc.; 7National Institute of Standards and Technology
Every pound of aluminum or aluminum alloys cast and sold is certified to meet The Aluminum Association Inc. registered limits or other specified composition limits. Certification of aluminum and aluminum alloys to specified composition limits is typically done using Spark-Atomic Emission Spectrometry (Spark-AES) following the procedures in ASTM International Standards. Spark-AES Laboratories at major aluminum production facilities normally have excellent analytical practices and follow strict quality control protocols to provide the best results possible. However, every measurement has an associated uncertainty and the measurement of composition using Spark-AES is no exception to the rule. This paper provides a brief discussion of this uncertainty, benefits of using guard bands to set internal operating limits, a model of the risk for sale of out-of-specification products, the main sources of uncertainty of Spark-AES and their potential causes.
3:45 PM Break
Laser Marking and 3D Imaging of Aluminum Products: Alex Fraser1; Michaël Dallaire1; Martin Hartlieb2; 1Laserax Inc.; 2Viami International Inc.
Most industrial products have (challenging) 3D shapes, many of them require traceability and individual marking. Although some laser marking systems on the market have 3D capabilities, they require the 3D shape to be loaded in the laser controller and the part to be precisely located. However, many industrial processes requiring direct part identification cannot fulfill those precise positioning requirements. To overcome these limitations, a 3D laser marker with integrated 3D imaging system was developed. This imaging system obtains the 3D image of the piece, then the laser controller starts the marking process so that the focus fits on the part surface. The whole 3D data acquisition and transfer takes less than 3 seconds. This solves the problem of part positioning and simplifies the integration, while also providing 3D data of the surface that can be used for quality control.
Production and Certification of Arconic Certified Reference Materials: Jenee Jacobs1; Michael Ruschak1; John Genna2; Keith Trichan2; Louis Bono1; Samantha Stephens1; 1Arconic Spectrochemical Reference Materials; 2Alcoa Spectrochemical Standards
Arconic Spectrochemical Reference Materials, formerly Alcoa Spectrochemical Standards, has been a leading producer of certified reference materials (CRMs) used by the aluminum industry for more than 70 years. Arconic offers more than 320 catalog alloys as well as custom specification alloys, all of which are produced by casting techniques that minimize or substantially eliminate both macro and micro segregations. The alloy compositions are certified for up to 28 elements using two or more independent analytical methods; most commonly Spark-AES, ICP-AES, and GD-MS; and rigorous statistical analysis to ensure the accuracy of the final composition certification, the chemical and physical uniformity, and the performance of the CRMs in use. The Arconic Spectrochemical Reference Materials’ process is ISO Guide 34, ISO 17025, and ISO 9001 accredited. This paper describes the production, analysis, and certification techniques used by Arconic Spectrochemical Reference Materials for the production and certification of CRMs.
Characterization of Large Strain Extrusion Machining (LSEM) of AA7050: Daniel Klenosky1; David Johnson1; Srinivasan Chandrasekar1; Kevin Trumble1; 1Purdue University
This work features a characterization of AA7050 strip produced via large strain extrusion machining (LSEM), which has emerged as an alternative method to produce AA7050 strip. LSEM plate or sheet is particularly attractive for applications where SCC and exfoliation cracking resistance are important. LSEM has been shown to produce grains with a lower aspect ratio than conventional hot rolling, which has been linked to SCC resistance. In addition, LSEM grains have a different orientation relative to the strip direction, which may result in an improvement in exfoliation cracking resistance as compared to hot-rolled strip.
Rare-earth Modified Aluminum Alloys for High-temperature Applications: Zachary Sims1; David Weiss2; Orlando Rios1; Scott McCall3; Ryan Ott4; Michael McGuire1; Tony Van-Burren3; Ke An1; Yan Chen1; 1Oak Ridge National Laboratory; 2Eck Industries; 3Lawrence Livermore National Laboratory; 4Ames National Laboratory
Aluminum Cerium alloys offer many benefits over traditional aluminum alloys. They exhibit: good mechanical properties at ambient temperature; exceptional mechanical properties at high-temperature when compared to existing alloys; and are highly castable via traditional foundry methods. Furthermore, some newly cast compositions of Al-Ce-X alloys appear to not require heat-treatment considering their as-cast properties are sufficient for some end-user application. In this talk we will discuss recent developments in the characterization of the Al-Ce-X alloy family. Phase by phase load partitioning has been measured via neutron diffraction at the SNS Vulcan User Facility. Microstructure evolution at elevated temperatures has been studied using Small angle X-ray (SAXS and μSAXS) scattering. In addition, high temperature mechanical properties have been measured for multiple binary, ternary, and quaternary alloy compositions at temperature up to 300 °C and compared with existing alloys.