Resistance Of Titanium Alloys Research Articles

Salt corrosion of titanium alloys

1. The long-term strength (1000 h) of commercial titanium alloys does not decrease under the influence of a film of NaCl at temperatures of 250° or lower. 2. With increasing testing temperatures the susceptibility of the alloys to salt increases. 3. Natural sea salt is more corrosive than NaCl at temperatures of 250° and higher. 4. The corrosion resistance of titanium alloys in contact with salt depends on the microstructure and the chemical composition of the alloy.

Resistance of titanium alloys to repeated static loads

1. With static loading a gas-saturated layer 0.1 mm thick on titanium alloy VT68 in the heat treatd condition lowers the strength some what and sharply lowers the ductility, particularly local ductility. 2. Removal of the gas-saturated layer by etching to a depth of 0.1 mm (alloy VT6S) and to a depth of 0.05 mm (VT14) increases the durability three to four times in repeated static loading. 3. The kinetics of failure of alloy VT6S in repeated static loading indicates that the gas-saturated layer affects mainly the number of cycles before a fatigue crack occurs. A crack occurs in the first cycles in samples with an unetched gas-saturated layer. 4. In biaxial tension the presence of a gas-saturated layer on alloy VT14 has little effect on the strength but induces brittle fracture. In repeated static biaxial tension the durability of alloy VT14 with a gas-saturated layer is two orders lower than that of samples without a gas-saturated layer.

Determination of the heat resistance of titanium alloys

Determination of the heat resistance of titanium alloys

Elevated Temperature Stress Corrosion Resistance of Titanium Alloys

Abstract A number of titanium alloys considered suitable for use in Mach II and III transports were tested for resistance to stress corrosion in the presence of chlorides. These included 4A1-3Mo-1V, 6A1-4V, 8A1-1M0-1V, 5A1-2.5Sn and RS-140. Samples were exposed stressed (smooth and fatigue pre-cracked) at 600, 700 and 800 F (316–427 C) 100 hours for smooth and 50 hours for precracked specimens. Welded and heat-treated specimens were among those tested. All alloys were found susceptible to stress corrosion cracking. Welding appeared to increase susceptibility, but existing fatigue cracks did not seem to increase susceptibility.

Corrosion Resistance of Titanium Alloys Compared With Commercially Pure Titanium

Abstract Titanium-8 percent manganese, titanium-5 percent aluminum-2½ percent tin, titanium-2 percent aluminum, titanium-6 percent aluminum, titanium-1 percent copper, and titanium-5 percent copper alloys are similar to commercially pure titanium in chemical and galvanic corrosion properties. These alloys are completely resistant to corrosion in synthetic ocean water, tap water, 1 percent sodium hydroxide, and 5 percent ferric chloride solutions. In sulfuric acid solutions saturated with air, the titanium alloys with the exception of those containing copper are resistant to corrosion in 5 percent solution at 35 C but corrode rapidly in 10 percent solution. At 60 C, these alloys are inert in 1 percent and corrode in 5 percent acid. The titanium-copper alloys usually are more resistant than commercially pure titanium to corrosion in sulfuric acid solutions and less resistant in hydrochloric acid. In contact with aluminum in 0.5 percent sulfuric acid saturated with air, titanium and the titanium-base alloys are the cathodic members of the couples. Titanium and titanium-base alloys are generally anodic when in contact with stainless steels in air-saturated 4.7, 9.3 and 17.5 percent sulfuric acid solutions but the galvanic corrosion rates are low. Furthermore, the chemical corrosion of titanium alloys is almost eliminated as a result of contact with stainless steel. 6.3.15