Fretting Wear Behavior and Damage Mechanisms of Inconel X-750 Alloy in Dry Contacts

Ibrohim A Rustamov,Ozoda Sh Sabirova,Yuming Wang,Zixi Wang

doi:10.1155/2019/7079819

Abstract

Tribological behavior of the Inconel X-750 alloy disk subjected to fretting against the GCr15 steel ball was investigated in an ambient laboratory air with relative humidity of 55–65%. A high-frequency oscillating Optimol SRV 4 tribometer was employed to execute dry fretting tests in the partial and gross slip regimes under constant 100 N normal load. Tests were carried out for 10, 30, and 90 minutes, and the friction forces vs. displacement amplitudes were monitored during the test duration. Posttest examinations were conducted utilizing advanced tools such as 3D optical surface profiler, scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX). The main objective was to obtain wear scar evolutions, frictional properties, and degradation mechanisms under the different running conditions over time. It was found that fretting wear behaviors of friction pairs were strongly influenced by fretting regimes. Degradation evolutions were greatly influenced by fretting time during partial slip regimes, i.e., evolving from asperity deformation and slight damage to the fatigue crack and material transfer. However, the combination of adhesive, abrasive, delamination, and wear oxidation mechanisms was repeated during the entire gross slip fretting process.

Highlights

Fretting maps which are proposed by Vingsbo and Soderberg [3] and developed by Zhou and Vincent [5] are used nowadays to represent the fretting regimes and Advances in Materials Science and Engineering damages based on the normal load and the displacement amplitude (Figure 1(a)). e relationship between tangential force and imposed displacement amplitude, the so-called “fretting loop,” was closed, elliptical and parallelogram during stick, partial slip, and gross slip conditions, respectively
Most of the fretting wear experiments have been conducted on the nickel-based nuclear engineering materials, such as Inconel 600, 690, and 690 TT alloys which are known for their corrosion and oxidation resistance in the elevated temperatures [14,15,16,17,18,19]. e effects of different fretting parameters and material properties were investigated in their study to evaluate different degradation mechanisms and fretting behaviors
Ball-on-flat fretting experiments were run at room temperature of 20–25°C using the SRV 4 (Optimol Instruments, Germany) high-frequency oscillation system with 50–60% air humidity in dry condition. e test rig is equipped with a soundproof chamber, integrated electronic measurements, load cell, oscillating rods, and other modules to control fretting parameters as shown in Figure 2. e lower Inconel X-750 disk specimen with 24 mm diameter × 7.8 mm height was fixed by clamps and subjected to the fretting by upper oscillating GCr15 (Chinese GB 308–89) steel ball with diameter of 10 mm and roughness of 0.025 μm (Ra)

Summary

Introduction

Fretting maps which are proposed by Vingsbo and Soderberg [3] and developed by Zhou and Vincent [5] are used nowadays to represent the fretting regimes and Advances in Materials Science and Engineering damages based on the normal load and the displacement amplitude (Figure 1(a)). e relationship between tangential force and imposed displacement amplitude, the so-called “fretting loop,” was closed, elliptical and parallelogram during stick, partial slip, and gross slip conditions, respectively. At 40 μm displacement amplitude, the contact is subjected to partial slip with junction of adhesion and sliding zones; the tangential force remains less than the product of applied normal load and the static friction coefficient.

Results

Conclusion