The Effect of the Strain Rate on the Fretting Wear Properties of Thermally Compressed Inconel 625 Alloy

Abstract

The strain rate during the thermal deformation process has a decisive effect on the performance of the material. Herein, Inconel 625 alloy is subjected to thermal compression at different strain rates to obtain fretting wear samples with different microstructures. The effects of the recrystallized grain morphologies, textures, and microhardness values on the fretting wear resistance of thermally compressed Inconel 625 are studied. The results demonstrate that the thermally compressed Inconel 625 alloy underwent severe oxidation reactions during fretting wear, mainly Fe oxides. At an equal temperature, as the strain rate of thermal compression increases, the friction coefficient and wear volume are found to first decrease and then increase. When the strain rates during thermal compression are 0.1 and 1 s−1, the workpiece is in a relatively fine recrystallized grain form without texture and with high hardness. At this time, the thermally compressed Inconel 625 has a low friction coefficient, a small volume of wear, and a large number of oxides on its surface. Therefore, the thermal deformation microstructure has a great influence on the wear resistance. Improvement in the fretting wear resistance of the workpiece by adjusting the strain rate during the thermal deformation process is proposed.

Thermal Deformation Behavior and Microstructure Evolution of GH4151 Alloy

“…[ 21 ] When the curve enters the flow‐softening stage, nickel‐based superalloys may experience discontinuous dynamic recrystallization (DDRX) at original grain boundaries, twin boundaries, subgrain boundaries, and carbides, with a typical necklace structure. [ 22 ] For cast nickel‐based superalloys with low atomic diffusion and mobile grain boundaries, both the deformation resistance and required deformation thermal activation energy are high. Thus, high temperatures and strain rates are required to obtain a sufficient activation energy to initiate DRX.…”

Evolution of Stacking Fault and Dislocation during Dynamic Recrystallization of Inconel 625 Alloy

“…Inconel 625 is one of the most widely used nickel-based wrought superalloys, which is used in aerospace, marine, nuclear power, and other fields. [1,2] It is very important to control the dynamic recrystallization (DRX) grains of inconel 625 alloy during hot deformation for its microstructure and comprehensive properties. [3][4][5] The DRX process of Inconel 625 alloy is not only related to the deformation parameters (such as temperature, strain rate, and true strain), but also to the dislocations and stacking faults (SFs) produced in the recrystallization process.…”