Eutectoid nanostructure formation in Ti-xPd alloys and its effects on mechanical properties and cytotoxicity

A series of Ti-xPd alloys with Pd contents ranging from 5 to 20 wt% were prepared in this study and the effects of Pd addition on microstructure, mechanical properties, corrosion behavior and cytotoxicity of Ti alloys were investigated. XRD analysis, optical microscopy, SEM, and TEM results indicated that the phases/crystal structure of the binary Ti-xPd alloy was sensitive to its Pd content in the cast alloy. We also studied the effect of alloying element Pd on the mechanical properties (including Vickers hardness and modulus) and corrosion behaviors of Ti-xPd binary alloys. Commercially pure titanium (cp-Ti) was used as a control. The additions of Pd to titanium increased the hardness by a factor of more than two. Electrochemical results showed that the Ti-xPd alloys exhibited corrosion resistance superior to that of cp-Ti. The cytotoxicities and cell viabilities of Ti-xPd alloys were comparable to those of cp-Ti. The addition of small quantities of alloying Pd metal significantly improved the mechanical properties of cp-Ti. Of all the alloys tested in this study, Ti-10Pd showed a great potential for use as a dental material.