Contents lists available at ScienceDirect Materials Science & Engineering A journal homepage: www.elsevier.com/locate/msea Nondestructive measurements of flow properties of nanocrystalline Al-Cu-Ti alloy using Automated Ball Indentation (ABI) technique Hany R. Ammar a,c, ⁎ , Fahmy M. Haggag b , Abdulaziz S. Alaboodi a , Fahad A. Al-Mufadi a a Mechanical Engineering Department, College of Engineering, Qassim University, Buraidah, Saudi Arabia b ABI Services-USA, LLC, 253 Midway Lane, Oak Ridge, Tennessee 37830, USA c Metallurgical and Materials Engineering Department, Faculty of Petroleum and Mining Engineering, Suez University, Suez, Egypt ARTICLE INFO Keywords: Stress-Strain Microprobe (SSM) system Automated Ball Indentation (ABI) Nondestructive measurements Flow properties Nanocrystalline Al-10Cu-5Ti alloy ABSTRACT The Stress-Strain Microprobe® (SSM) system and its Automated Ball Indentation® (ABI®) test technique were applied in the present study for the purpose of determining the flow properties of the alloy under study in a non- destructive manner. ABI tests were applied at 21 °C to the consolidated nanocrystalline Al-10 wt% Cu-5 wt% Ti alloy samples which were subjected to three and six hours of milling. The samples processed for six hours of milling were further tested at elevated temperatures of 200 °C and 400 °C. The results of the ABI tests of the alloy under study include the indentation load versus depth of penetration curves, true stress versus true-plastic-strain curves, determination of yield strength curves, ultimate tensile strength values, and ABI Brinell hardness number (BHN). X-Ray Diffraction (XRD) was applied to investigate the microstructure of the Al-10 wt% Cu-5 wt% Ti alloy subjected to different milling time before and after consolidation. XRD analysis includes identification of the main phases/elements present and calculating the crystallite size in the processed alloy for 3 and 6 h of milling before and after consolidation. Apreo Field Emission Scanning Electron Microscope was applied to characterize the size and morphology of the indentation area after conducting the ABI tests. In addition, the same technique was applied to reveal the elemental distribution in the indentation area of the tested samples. 1. Introduction Aluminum alloys display obvious potential for several engineering applications due to their specific advantage of high strength-to-weight ratio which leads to decreasing fuel consumption and enhancing me- chanical performance. Mechanical alloying technique has been used for synthesizing super-alloys which results in producing dispersion- strengthened Al alloys. Numerous alloys have already been produced using ball milling, such as Aluminum-Magnesium, Aluminum-Titanium and Aluminum-Zirconium alloys. High strength Aluminum-Titanium alloys have also been developed for high-temperature applications through dispersion of Al 3 Ti nano/submicron particles in the matrix [1,2]. Aluminum-iron alloys are additional sets of aluminum alloys with improved properties even at high-temperatures [3–6]. The Stress-Strain Microprobe (SSM) system and its Automated Ball Indentation (ABI) test technique were patented by Advanced Technology Corporation (ATC) [7]. This novel system was developed for the purpose of testing minimal material to measure the major me- chanical properties in a nondestructive manner. The measured me- chanical properties using this technique include flow properties, ulti- mate tensile strength, yield strength and hardness values. The SSM system and its ABI test method were developed based on recognized and validated physical and mathematical relations which control the behavior of metals under multi-axial indentation loading [7,8]. More details about the ABI technique are found in the following references [7,9–11]. The ABI technique, as a non-destructive test, was successfully ap- plied to evaluate the flow properties of several materials such as iron- based and steel alloys [12–15], titanium alloys [16], aluminum alloys [17], zirconium alloys [18,19] and soldering materials [20,21]. The reported results of ABI testing were in accordance with those from traditional standard tests. The ABI technique displays several inter- esting advantages [22], such as using small size samples without es- sential specimen preparation, nondestructive measurement of me- chanical properties, simple test procedures, relatively rapid where the test takes few minutes, and generates interesting results which include yield strength, ultimate tensile strength, hardness and true-stress-vs- true-plastic-strain curve. Furthermore, it can be implemented for in-situ testing of components on service conditions. In addition, ABI tests can be accomplished at room, low, and elevated temperatures. The same technique can be used for nondestructive evaluation of fatigue, fracture toughness, and creep properties [23]. https://doi.org/10.1016/j.msea.2018.05.089 Received 1 February 2018; Received in revised form 14 May 2018; Accepted 23 May 2018 ⁎ Corresponding author at: Mechanical Engineering Department,College of Engineering, Qassim University, Buraidah, Qassim 51452, Saudi Arabia. Materials Science & Engineering A 729 (2018) 477–486 Available online 24 May 2018 0921-5093/ © 2018 Elsevier B.V. All rights reserved. T