Study On The Process Of A Novel Boronizing With Solid Boron Agent On Ti6Al4V Substrate

Titanium and its alloy are widely used in aerospace, biomedical, chemical and other industries due to their high ratio of strength to weight, high corrosion resistance and biocompatibility. However, the deficiencies of titanium alloy are obvious as well, such as insufficient wear resistance, low hardness. Surface modification is possible to solve these problems one way.Surface treatment of bonding can obviously improve the wear-resistance of the metal substrate. The traditional methods of boronizing have poor environment, low efficiency shortcomings, so a new plasma boronizing technology was employed using FeB as the precursor and source cathode and the process of plasma boronizing and properties of modified layer were investigated in this paper.The key issue of plasma boronizing with solid precursor was sputtering of source cathode FeB. And the temperature was vital for sputtering. Investigating the weight loss of bulk source cathode FeB at different temperatures, it was found that the higher the source cathode, the more of the loss weight of source FeB, the specimen's weight addition also increased with the temperature. Nevertheless the specimen also existed sputtering, after calculation, the highest absorptivity was about 1.12% at 1000℃. Two different solid states of FeB power and bulk were used. And their boronizing results were compared. It showed that the bulk surce cathode can get a better boronized modified layer.The micro-structure and distribution of composition were analyized. The results showed that a layer of boron element gradient distribution composed mainly of FeB andα-Ti andβ-Ti, and these XRD diffraction peaks had corresponded in XRD diffraction patterns of modified surface. The hardness of modified layer was significantly improved. Impacting tests showed that the modified alloying system had an excellent coordination deformability. Pin-on-Disc tests indicated that coefficient of the friction of modified layer increased while the width of wear tracks was remarkably smaller relative to the substrate, and wear resistance of treated samples was significantly improved. After boronization processing, the electrochemistry corrosion resistance of the treated specimens were not damaged obviously in 0.5mol/L H₂SO₄, 0.5mol/L NaCl and 0.5mol/L Na₃PO₄ solutions.