Abstract
In this study, we introduce a rapid boriding technique that can produce very thick titanium diboride (TiB2) layers on titanium substrates. We also discuss the effects of process duration on boride layer thickness, chemistry and, morphology. In our experiments, the boriding of commercial purity titanium (CP-Ti) substrates was carried out in an electrochemical cell in which we used a mixture of sodium tetraborate and sodium carbonate as the base ingredients of molten electrolyte at 950°C and at current density of 300mA/cm2. The titanium test pieces were attached to the cathode holder of the electrochemical cell while a graphite crucible served as the anode. Both TiB and TiB2 phases were detected by X-ray diffraction method even after 5min of treatment. Scanning electron microscopy (SEM) images verified that the production of 4.5μm thick TiB2 layers was feasible after boriding for an hour. The boride layers consisted of a homogeneous TiB2 phase on the top and TiB whiskers toward the substrate. The micro-indentation studies indicated that the layer on top has hardness values as high as 40GPa. The main advantages of this technique are its ability to produce very thick and hard TiB2 quickly and to create no gaseous emissions or solid wastes during or after the treatment.
Original language | English |
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Pages (from-to) | 3935-3939 |
Number of pages | 5 |
Journal | Surface and Coatings Technology |
Volume | 204 |
Issue number | 23 |
DOIs | |
Publication status | Published - Aug 2010 |
Keywords
- Electrochemical boriding
- Molten salt
- Surface treatment
- Titanium diboride