Study of α-Fe₂O₃ formation and its measurement in oxide films of wheel surface during ELID grinding process

Abstract

This paper presents the study of forming mechanism of [Formula: see text]-Fe2O3 in oxide films on electrolytic in-process dressing (ELID) grinding wheel surface. To investigate the component content and the microtopography of oxide films, XRD, XPS, IR spectrum analysis, SEM, and TEM measurements are performed on ELID grinding wheels. In XRD test results, the characteristic absorption band of [Formula: see text]-Fe2O3 is found in the oxide film. XPS tests show that there is full of ferrous iron and oxygen element in the oxide film. Also, the characteristic spectral line of XPS is identical to the standard spectrum of [Formula: see text]-Fe2O3. Several vibration peaks (471, 1029, 1384, 1630, 3430) are observed by IR spectrum analysis. It can be easily seen by contrast with the standard photographs that the vibration peak of 1029 is of Fe-O vibration band in IR spectrum of [Formula: see text]-Fe2O3 powder. Therefore, these measurement results confirm the existence of [Formula: see text]-Fe2O3 in the oxide films, and explain the polishing effect of oxide films during ELID grinding. The fresh oxide film is porous and moisture rich. However, the oxide film after squeezing to dry is investigated by SEM imaging to present tortoiseshell cracks. Geometrically, [Formula: see text]-Fe2O3 appears to be nearly spherical with particle size around 5–50 nm. This indicates fine polishing improvement by oxide films, and is identified as the mechanism responsible for excellent surface quality by ELID grinding.

ELID Dressing Behaviors of Non-Abrasive Iron-Based Grinding Wheels

“…Large quantities of α-Fe 2 O 3 particles are favorable, serving as an excellent agent for polishing in place of abrasive particles. Due to the absence of abrasive particles, our new diamond wheels address the issue of passivating particles that may detach and scratch the processed surface [35,36].…”

Experimental study on the characteristic and function of oxide film formed on grinding wheel in ELID precision grinding

“…He studied the mechanical properties of oxide films on copper-based grinding wheels using the nanoindentation technology. Through experiments, he found that the hardness and elastic modulus of the oxide film are higher than those of the copper-based grinding wheel (Kuai et al, 2017a(Kuai et al, , 2017b(Kuai et al, , 2017c. He also studied forming mechanism of a-Fe 2 O 3 in oxide film on ELID grinding wheel surface and found that the oxide film can improve the grinding effect and the processing quality (Kuai et al, 2017a(Kuai et al, , 2017b(Kuai et al, , 2017c.…”

Manufacturing Technology of α-Fe Bonded Grinding Wheel Free Abrasive

“…Owing to the surface precision of ultra-precision ELID grinding has reached nanometer level [3,4]. Therefore, any minor scratch will form defects on the machined ultra-precision surface, which will affect the surface quality [5]. There is a need to regrinding with no abrasive particles in the ultra-precision grinding stage.…”