Investigation of Ti-5Al-2.5SnELI and Ti-5Al-2.5ZrELI Used at Cryogenic Temperature

摘要

In this study the mechanical and physical properties at 4.2K, 20K and room temperature of Ti-5Al-2.5SnELI and a new cryogenic used titanium Ti-5Al-2.5ZrELI is investigated. The study consists of the effects on the properties of variations in composition of aluminium and oxygen, zirconium in stead of tin. The study also investigates their deformation behavior and fracture mechanism. The results show that variations in aluminium composition of Ti-5Al-2.5SnELI has much more influence on the mechanical properties at room temperature than at 4.2K and 20K temperature.The new cryogenic titanium alloy Ti-5Al-2.5ZrELI has more consistent properties as its uniform structure and less segregation. It has good strength combination with elongation and ductility. Their deformation mode at RT is twinning combination with slipping and their fracture surfaces are covered with elongated dimples at cryogenic temperature especially specimens of Ti-5Al-2.5SnELI and specimens with larger grains.