In Situ Observation of the Tensile Deformation and Fracture Behavior of Ti–5Al–5Mo–5V–1Cr–1Fe Alloy with Different Microstructures

Abstract

The plastic deformation processes and fracture behavior of a Ti–5Al–5Mo–5V–1Cr–1Fe alloy with bimodal and lamellar microstructures were studied by room-temperature tensile tests with in situ scanning electron microscopy (SEM) observations. The results indicate that a bimodal microstructure has a lower strength but higher ductility than a lamellar microstructure. For the bimodal microstructure, parallel, deep slip bands (SBs) are first noticed in the primary α (αp) phase lying at an angle of about 45° to the direction of the applied tension, while they are first observed in the coarse lath α (αL) phase or its interface at grain boundaries (GBs) for the lamellar microstructure. The β matrix undergoes larger plastic deformation than the αL phase in the bimodal microstructure before fracture. Microcracks are prone to nucleate at the αp/β interface and interconnect, finally causing the fracture of the bimodal microstructure. The plastic deformation is mainly restricted to within the coarse αL phase at GBs, which promotes the formation of microcracks and the intergranular fracture of the lamellar microstructure.

Initial Microstructure Effects on Hot Tensile Deformation and Fracture Mechanisms of Ti-5Al-5Mo-5V-1Cr-1Fe Alloy Using In Situ Observation

“…This indicates that dislocation slip is the dominant deformation mechanism of the α phase at the applied temperature [22]. Our previous study indicated that pyramidal slip is difficult to take place within the α P phase which is more likely to slip along its basal or prismatic plane at room temperature [23]. In the present study, Figure 10b-d show that prismatic slip ({1100}<1120>) and pyramidal slip ({1101}<1120>) were prevalent in the α P phase compared with basal slip ({0001}<1120>).…”

Optical Strain Measurement and Microfractography of the Fractures of Armstal 550 Steel after Temperature Tensile Tests

“…Numerous examples of studies in which material strength investigations and mi fractography research were combined to extend the investigations can be found in contemporary literature [16][17][18][19][20], some of which deal with investigations at different t perature levels. DIC measurement is currently the most important noncontact strain measurement method and is constantly being further developed [7][8][9][10].…”

“…Numerous examples of studies in which material strength investigations and microfractography research were combined to extend the investigations can be found in the contemporary literature [16][17][18][19][20], some of which deal with investigations at different temperature levels.…”

Effect of a Compound Energy Field with Temperature and Ultrasonic Vibration on the Material Properties and Bending Process of TC2 Titanium Alloy

“…In the process, the material requirements and the function requirements mutually prompt each other. Titanium alloys have numerous advantages over other metal materials, including low density, high strength, high- and low-temperature resistance, superior corrosion resistance, and good compatibility with composite materials [ 1 , 2 , 3 , 4 , 5 ]. As a result, titanium alloys play an irreplaceable role compared to other metals.…”