Effect Of Rare Earth Ytterbium On Mechanical Properties Of Ti-1100 Alloy

Titanium alloys are widely used in aviation,aerospace,chemical industry,ship and other industries as excellent mechanical properties,such as high strength,good fracture toughness,high temperature resistance and corrosion resistance.Firstly,the mechanical properties and research status of Ti-1100 alloy were introduced.Secondly,the research status of rare earth elements on the mechanism of Ti,Mg and other alloys was summarized.Thirdly,the effect of Yb on the mechanical properties of Ti-1100 alloy was explained.Inner Mongolia University of Science and Technology Innovation Fund Project?2016QDL-B11?supports this research.The effect of ytterbium?Yb?on the mechanical properties of Ti-1100 alloy was studied,in which ytterbium was added in the form of Yb₂O₃.Preparation of Ti-1100-xYb₂O₃ Alloys with Different Yb₂O₃ Contents by Tungsten Electrode Non-consumable Arc Furnace.Constant temperature and constant strain rate compression tests of the alloy were carried out at 25,300,600 and 800?,strain rates of 10^-4,10^-3 and 10^-2s^-1 by using high temperature furnace and WDW-300 electronic universal testing machine.The true stress-true strain curves of Ti-1100-xYb₂O₃ alloy during compression deformation were obtained.The deformation behavior and the effect of Yb₂O₃ on the mechanical properties of as-cast alloy were analyzed.Yb₂O₃ addition in Ti-1100 alloy can significantly improve the yield strength.The yield strength and compressive strength of the alloy increase first and then decrease with the increase of Yb₂O₃ content at 25⁶00?.When the content of Yb₂O₃ in the alloy is0.45wt%,the yield strength and compressive strength of the alloy increase to the extreme value.The results show that the mechanical properties of Ti-1100-xYb₂O₃ alloy are the best when the content of Yb₂O₃ is 0.45wt%at 25⁶00?.The mechanical properties of the alloy with Yb₂O₃ content of 0.60wt%are the best when the temperature is 800?.Microstructure and fracture morphology of the alloy were observed by scanning electron microscopy?SEM?.The addition of Yb₂O₃ refines the?lamellar spacing of the alloy,especially when the content of Yb₂O₃ is 0.45wt%.Yb₂O₃ improves the high temperature mechanical properties of as-cast Ti-1100-xYb₂O₃ alloy.When the content of Yb₂O₃ in Ti-1100xYb₂O₃ alloy is 0%,0.30%and0.45wt%,the dimple fracture with river pattern accompanied by ductile fracture characteristics is the main section.When Yb₂O₃ content in the alloy is 0.45wt%,the dimple area is the largest,indicating that the plasticity is the best.When the content of Yb₂O₃ in the alloy is 0.60wt%,there are almost no dimples in the river pattern and the material is relatively brittleness.In order to characterize the relationship between rheological stress and deformation temperature,strain rate and strain variables of materials.Based on Arrhenius hyperbolic sinusoidal constitutive model,a mechanical constitutive model considering strain phase is proposed.Constitutive equations of Ti-1100 and Ti-1100-0.45Yb₂O₃ alloy have been established.The reliability of the model is verified by comparing the calculated value with the experimental curve and calculating the absolute value of the average relative error AARE.