Cu‐Ti, Co‐Ti and Ni‐Ti systems: corrosion and microhardness

Abstract

Titanium alloys of 10 wt%-72 wt% Cu, 10 wt%-80 wt% Co and 20 wt%-84 wt% Ni were investigated. Ingots were fabricated in a vacuum/argon tungsten arc furnace. The surfaces of the alloys were examined by optical microscopy and SEM/EDS, and the Knoop hardness values of the alloys were measured. The corrosion resistance of the alloys was determined by a potentiodynamic polarization technique in buffered Ringer's solution. When a threshold composition of 30 wt% alloy was reached, a large decrease in corrosion resistance was found to occur. Knoop hardness measurements showed that similar hardness values of approximately 300 KHN can be obtained in all systems with lower alloy content. These values are similar to those obtained with a commercial dental titanium alloy.

Biocorrosion study of titanium‐nickel alloys

“…The casting chamber was evacuated and argon was cycled at least three times prior to melting in a water-cooled copper heart. A similar technique has been used to successfully fabricate other titanium-based alloys including Ti-Pd, Ti-Cu, Ti-Ni, and Ti-Co (Moser etal, 1985;Chern Lin et al, 1990). The castings were then sealed in vacuum in quartz tubes and homogenized for 40 h at 900°C, followed by a heat treatment at 760°C, for 2 h and furnace-cooled to room temperature (25°C).…”

“…Despite the various advantages, the high melting temperatures and strong tendency to oxidize and react with mould materials make pure and low alloy titanium difficult to fabricate by casting (Takahashi et al, 1990). Some high alloy systems such as Ti-Co, Ti-Cr, Ti-Cu, Ti-Mn, Ti-Ni, Ti-Pd and others (Ida et al, 1982;Moser etaL, 1985;Chern Lin et aL, 1990;Ito, 1990;Akagi et aL, 1992) have been explored in an attempt to lower the melting temperature, as well as improve some mechanical properties. Corrosion resistance of such titanium alloys, however, usually decreases when large amounts of alloy materials are added (Chern Lin etal., 1990):…”

Effect of potential on the corrosion behavior of a new titanium alloy for dental implant applications in fluoride media

“…The high melting temperature (1700 8C) and extreme difficulty in casting [4] hinder the use of Ti in prosthetic dentistry. Thus, Ti-alloys, with a significantly lower casting temperature would be very useful.…”

“…Thus, Ti-alloys, with a significantly lower casting temperature would be very useful. Chern and his group [4] found that adding Cu or Co at < 30 weight % lowered the melting point of Ti, and maintained superior passive properties. Al-Jabab [5] developed six different new low melting ternary alloys, xTi-yAg-zCu (x ¼ 50 or 60, y ¼ 40 to 10, z ¼ 10 to 30), and found that 60TiyAgzCu alloys had excellent castability, chemical and acceptable mechanical properties that gave them a great potential for future use as dental alloys.…”

Structure, castability and mechanical properties of commercially pure and alloyed titanium cast in graphite mould

“…Because of their high strength‐to‐weight ratios, excellent mechanical properties and corrosion resistance (1–3), titanium and titanium alloys have become one of the backbone materials for many aerospace (4), energy (5), sports, marine (6) and chemical applications. Titanium is also used for dental (crown and bridge, framework, dental implant, etc.)…”