Effect of high energy Ar-ion milling on surface of quenched low-carbon low-alloyed steel Tibor Berecz 1,a , Szilvia Kalácska 2,b , Gábor Varga 2,c , Zoltán Dankházi 2,d , Károly Havancsák 2,e 1 Budapest University of Technology and Economics, Department of Materials Science and Engineering 1111 Budapest, Bertalan Lajos utca 7., Hungary 2 Eötvös Loránd University, Department of Materials Physics 1117 Budapest, Pázmány Péter sétány 1/a. a: berecz@eik.bme.hu (corresponding author); b: kalacska@metal.elte.hu; c: bagoj@caesar.elte.hu; d: z.dankhazi@szft.elte.hu; e: hkaroly@caesar.elte.hu Keywords: Specimen preparation, Ion milling, SEM, EBSD. Abstract. Surface preparation for electron backscatter diffraction (EBSD) measurements requires a lot of time and experience. We chose a lath martensitic iron based alloy to demonstrate the efficiency of ion polishing techniques. The average image quality (IQ) values from the EBSD measurements were assigned to be the characteristic parameter for surface goodness. The ideal ion sputtering time and the angle of incidence were determined, and the corresponding inverse pole figure (IPF) and IQ maps were compared to the mechanical polishing treatment. Introduction Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) play a key role in the experimental research work of materials science and solid state physics. At the same time, however to a different extent, both methods request demanding sample preparation. The traditional sample preparation techniques, such as mechanical or electro-polishing methods can hardly satisfy all demands, and they are usually time consuming treatments. The mechanical surface treatment has another drawback; after grinding and polishing an amorphous layer of 1-100 nm thickness remains on the surface. The name of this amorphous layer is the Beilby layer [1]. The removal of this layer is difficult or needs long time careful mechanical treatments. These are the reasons that in the last decades a new promising technique has been spreading. This new method is based upon the ion milling, the physical basic of which is the sputtering of atoms. Different ion beam methods have been used in the last decades for TEM lamella thinning or to prepare flat sample surface and cross sectional specimens for SEM measurements. These methods use either low energy (0,1-2 keV) or relatively high energy (2-10 keV) ions of inert gases (e.g. Ar + , Kr + ) or some ions of metallic origin, as for instance Ga + ions in the focused ion beam (FIB) technique. Ion milling is the erosion of solid surfaces due to ion bombardment. During ion milling the incident ions transfer energy to the atoms of the target through collisions. If the target atoms gain sufficient energy (more than the surface binding energy) then they escape from the surface. The rate of this erosion depends mainly on the material of the target (via surface binding energy) and the energy density given to the surface target atoms. This energy density depends on the mass, the energy, and the direction of the incident ion beam [2, 3]. The electron backscatter diffraction (EBSD) is an optional application in scanning electron microscopy to characterize the grain parameters, the texture and phase features of a polycrystalline material. In an EBSD measurement the SEM sample is tilted at ~70°. The result of a diffraction measurement is the so called Kikuchi pattern detected by a special detector containing a high resolution fluorescent screen and a CCD camera behind it. The Kikuchi pattern contains Kikuchi Materials Science Forum Vol. 812 (2015) pp 285-290 © (2015) Trans Tech Publications, Switzerland doi:10.4028/www.scientific.net/MSF.812.285 All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of TTP, www.ttp.net. (ID: 152.66.32.36, Budapest University of Technology and Economics, Budapest, Hungary-04/02/15,11:37:06)