Iranian Journal of Manufacturing Engineering

Iranian Journal of Manufacturing Engineering

A hybrid lapping/anodizing technique for surface modification of the tungsten carbide mechanical seals used in direct reduction plant compressors of steel production industries

Document Type : Original Article

Authors
Hadi Allahvakil 1
Hamid Zarepour Firouzabadi 2
1 MSc Student, Department of Mechanical Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Iran
2 Assistant Professor, Department of Mechanical Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Iran
10.22034/ijme.2024.433486.1909
Abstract
Mechanical seals are among the most widely used components of pumps and compressor. These parts consist of stationary and rotary sections with proper hardness and surface quality. The rotary surface is moving on the stationary surface while sealing should be performed between them. Hence, surface quality of the mechanical seals is critical for their performance. Lapping is a suitable finishing process used to improve the flatness and smoothness of mechanical seal surfaces. However, there is a lack of sufficient and extensive researches in the field of optimizing the lapping parameters of mechanical seals made of tungsten carbide. This study aimed to optimize the lapping time and pressure for tungsten carbide material to improve the flatness and roughness of the mechanical seals. To achieve this aim, a novel approach was used that combines anodizing and lapping. Experiments were conducted on both anodized and non-anodized samples. The results showed that anodizing reduces the surface hardness of tungsten carbide by 50%, which can reduce the maximum lapping time from 17 hours to less than 4 hours. The oxide layer on the surface of the samples was also completely removed after lapping, as confirmed by scanning electron microscopy. Moreover, the results of 2D and 3D topography showed that the surface roughness and flatness of the anodized samples were both improved compared to the non-anodized samples.
Keywords
Lapping Process
Mechanical Seals
Process Parameters
WC Anodizing
Surface Characteristics
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