Ultra Fast Boriding : An Overview

O.L. Eryilmaz, O. Kahvecioglu and, A. Erdemir
Argonne National Laboratory,
United States

Keywords: boriding, surface technology, wear, friction, harsh conditions, productivity

Summary:

High-temperature surface treatment processes (such as nitriding, carburizing, and boronizing) are well-established and used widely by numerous industrial sectors to achieve superior mechanical, corrosion, and tribological properties on all kinds of engineering components made out of ferrous and non-ferrous materials. Unfortunately, these traditional processes are very slow and energy intensive, and they produce large amounts of CO2 emissions and liquid/solid wastes to deal with during and after each process run. From economic and environmental points of views, it is highly desirable to develop and implement a novel surface treatment technology that is quick, cheap, clean, and energy efficient. With the design and industrial-scale realization of a ultra-fast boriding process at Argonne National Laboratory, we have successfully demonstrated the treatment of large numbers of industrial components made out of both the ferrous and non-ferrous alloys in a batch-to-batch operation without creating any in-house gaseous emissions or producing solid and/or liquid wastes. With the use of this large unit, our team achieved very thick boride layers of 50-100 micrometers in minutes (i.e., 15-30 minutes) as opposed to 10 to 15 hours in the case of conventional pack boriding processes. Depending on the type of metal or alloy being treated, the hardness values ranged from 16 to 45 GPa. Overall, very thick (more than a quarter millimeter) and hard surface layers produced by ultra-fast boriding are expected to have a positive impact on the performance and durability of all types of machine components that are subject to corrosive, erosive, abrasive, and adhesive wear. Another transformational feature of ultra-fast boriding is that it does not create any greenhouse gas emissions or solid and/or liquid wastes to deal with during or after the treatment; hence, it is an ultra-green technology (no need for expensive waste disposal and/or treatment facilities). It may eliminate the use of natural gas and other carbon-based fuels as the primary energy source in the heat treatment industry (which is the most common practice at present), thus, minimizing the CO2, NOx, CO, and SOx emissions that are generated in large quantities by current heat treatment practices. The main ingredient used during boriding is borax, which is a safe/natural mineral. Overall, large-scale ultra-fast boriding is a transformational technology that can complement, if not replace, many of the energy- and carbon-intensive surface treatment processes that are in use today, such as conventional boriding, carburizing, nitriding, carbo-nitriding, and physical and chemical vapor deposition. It is proven to be an ultra-green, ultra-efficient process that can drastically reduce costs, increase productivity, and improve the performance and reliability of machine components used in cross-cutting industrial applications including manufacturing, transportation, aerospace, agricultural, earth-moving, and mining. With the treatment of machine components used in these industries by ultra-fast boriding, one can achieve very long life and efficiency, hence productivity and reliability.