Titanium slip systems

The preferred slip plane in ionic crystals with the halite (NaCl) structure, such as NaCl or LiF, is 110, and the slip direction used is (110). This slip system is sketched in Figure 10.17. For the more metallic halite structure solids such as titanium carbide (TiC), the slip system is similar to that in face-centred cubic metals, 1 1 1 (110). 

Titanium carbide has had the rock salt structure assigned to it, e.g. LiF, NaCl, MgO, etc. with slip system assumed to be of 110. However, the primary slip system turns out to be the one indicated above, namely 111, rather than 110, which is the characteristic slip system in FCC structures [27]. 

Since the number of slip systems is not usually a function of temperature, the ductility of face-centered cubic metals is relatively insensitive to a decrease in temperature. Metals of other crystal lattice types tend to become brittle at low temperatures. Crystal structure and ductility are related because the face-centered cubic lattice has more slip systems than the other crystal structures. In addition, the slip planes of body-centered cubic and hexagonal close-packed crystals tend to change at low temperature, which is not the case for face-centered cubic metals. Therefore, copper, nickel, all of the copper-nickel alloys, aluminum and its alloys, and the austenitic stainless steels that contain more than approximately 7% nickel, all face-centered cubic, remain ductile down to the low temperatures, if they are ductile at room temperature. Iron, carbon and low-alloy steels, molybdenum, and niobium, all body-centered cubic, become brittle at low temperatures. The hexagonal close-packed metals occupy an intermediate place between fee and bcc behavior. Zinc undergoes a transition to brittle behavior in tension, zirconium and pure titanium remain ductile. 

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