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The aim of the current research is to characterize boride coatings on steels and steel alloys produced in a CVD fluidized bed reactor.

Heat treatments of alloys in fluidized bed reactors have been carried out for more than 25 years. Recently, this technology has been used for surface engineering applications in the deposition of hard and/or corrosion‐resistant layers. The present paper used fluidized bed technology (FBT) to deposit boride coatings on to ferrous materials. The coatings were examined by means of optical microscopy, Vickers microhardness measurements and X‐ray diffraction in terms of coating thickness and morphology, phase formation and hardness determination. The coating's tribological properties were evaluated under dry wear. Impact tests were also carried out to determine the fatigue resistance of the examined coatings under dynamic impact loading.

Boriding in a fluidized bed reactor is a simple, environmentally friendly and fast‐coating process. The produced iron‐boride coatings are characterized by excellent quality and uniform tooth‐shaped morphology. Fe₂B was the predominant boride phase formed, exhibiting superior tribological properties under dry wear conditions. Impact testing investigations revealed high‐fatigue strength of boride coatings in combination with limited deformable substrates.

The investigated coatings were deposited only on some structural and tool steel substrates.

Boride coatings deposited using FBT are satisfactory abrasive wear‐ and fatigue‐resistant coatings in comparison with those produced using common boride coating methods.

The outcome of the research is of great importance for the industry using abrasive wear coatings.

The purpose of this paper is to achieve a hard and protective borided layer on commercially pure Ti (grade-2) by applying boriding, and to investigate the changes in its microstructure, hardness, friction and wear behaviors.

Pack boriding technique was used to form a hard boron diffusion layer on titanium substrate. A powder mixture of amorphous boron and anhydrous borax was used as a solid-state boriding media, and then the boriding was carried out under inert atmosphere.

A thick dual boride layer consisting of a monolithic titanium diboride (TiB₂) on the top and titanium monoboride (TiB) whiskers beneath that layer formed at relatively low diffusion temperature under pressured inert argon atmosphere in a boriding media containing boron source and activator. With boriding at specified conditions, very hard (4100 Hv0.01) and thick monolithic TiB₂ layer formed on the top-most layer which is required for improved tribological applications. Hardness decreased gradually through the TiB whisker layer and finally reached to the hardness of base material.

This paper investigates the effects of components of boriding mixture and conditions of thermal treatment on the formation of borided layer and its properties. In previous studies, boriding mixtures containing a boron source, an activator and a filler material was generally used at high temperatures around or above 1,050°C to achieve a thick monolithic layer on the top of the surface of titanium. In the present study, no filler material was used to accelerate the boron diffusion because filler materials may inhibit the diffusion of boron atom through the surface of substrate of titanium. Also, diffusion treatment was carried out under pressurized argon atmosphere at relatively low diffusion temperature to achieve boride layer with the improved hardness and durability.