Effect Of Ti-Ion Implantation On The Mechanical And Corrosion Properties Of The Fecrni Super Alloy

Ari Handayani

doi:10.18502/ken.v1i1.454

Abstract

Ion implantation is widely used for surface treatment to modify the near surface properties of materials especially semiconductors without changing their bulk properties. In this work an investigation on the effect of implantation by Ti-ion on the mechanical properties and the wet corrosion of the high Cr and Ni content FeCrNi alloy was performed. Because of its superior properties this alloy is also well known as super alloy and often used as structure material in nuclear reactors. The alloy <del cite="mailto:USER" datetime="2016-05-18T11:01">was fabricated </del><del cite="mailto:USER" datetime="2016-05-18T10:59">at </del><del cite="mailto:USER" datetime="2016-05-18T11:01">BATAN </del><del cite="mailto:USER" datetime="2016-05-18T11:00">in </del><del cite="mailto:USER" datetime="2016-05-18T11:01">Bandung </del>containing <ins cite="mailto:USER" datetime="2016-05-18T10:38">of </ins>55.98 wt.% Fe , 23.46 wt.% Cr, 18.23 wt.% Ni and small amount of other metal elements<ins cite="mailto:USER" datetime="2016-05-18T11:01">, </ins><ins cite="mailto:USER" datetime="2016-05-18T11:01">was fabricated </ins><ins cite="mailto:USER" datetime="2016-05-18T11:01">in</ins><ins cite="mailto:USER" datetime="2016-05-18T11:01"> BATAN Bandung</ins>. The alloy sample was subjected to Ti-ion implantation in an ion generator with theoretical doses varied between 0.89x1016, 2.68x1016, 3.58x1016 and 10.75x1016 ion/cm2respectivelly. The hardness measurement was conducted with Vickers method and the corrosion resistance test was carried out in the borax acid (HBO3) environment. The microstructure of the material after implantation was characterized and analyzed by means of the Scanning Electron Microscopy (SEM) equipped with the Energy Dispersive X-Ray Detector (EDX) while the surface crystal structure was idenfied using X-Ray Diffraction (XRD). The result showed that the Ti implantation improved the surface hardness when the dose was higher than 3.58x1016 ion/cm2, while the corrosion resistance increased abruptly at all ion doses. However, no microstructure change could be observed on the cross section. A thin layer which is indicated by BSE image contrast was observed in the top most surface. Analysis on the EDS spectrum revealed that the layer could be considered to be the titanium oxide elucidating the increasing of hardness and exceptionally higher resistance to wet corrosion.

Highlights

Ion implantation is applied for modification of material surfaces where no change of final dimension allowed
Scanning Electron Microscopy (SEM) investigation is performed at constant electron ecceleration voltage 20 keV and standard work distance 10 mm fitted to Energy Dispersive X-Ray Detector (EDX) requirement
The hardness is nearly constant over the applied ion doses which is about 140 HV25

Summary

Introduction

Ion implantation is applied for modification of material surfaces where no change of final dimension allowed. Didyk et al used deuterium ion implantation by low energy ion irradiation beam line technique to create high hydrogen concentration in the subsurface area of some pure metals (Cu, Zr, Pd, Ti, V) and Pd-alloys [5] They observed nanosized defects on all samples as revealed by small angle X-ray scattering. As in the case of tool steels, the surface modification caused by ion implantation includes both a surface compression which prevents crack propagation and an alloying of the surface to make it more chemically resistant to corrosion. The study observed higher corrosion resistance in acidic solution It showed maximum hardness at dose 10.75x1016 ion/cm but no information about the Ti composition in the sample and the surface microstructure change after implantation. Nuclear facilities the alloy must full fill additional requirement namely its resistance under corrosive environment

Experimentals

Result and Discussion

Conclusion