טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentFadida Refael
SubjectDynamic Mechanical Behavior of Additively Manufactured
Ti6A14V with Controlled Voids
DepartmentDepartment of Design and Manufacturing Management
Supervisors Professor Daniel Rittel
Dr. Amnon Shirizly
Full Thesis textFull thesis text - English Version


Abstract

The mechanical properties of Additively Manufactured (AM) dense and porous Ti6Al4V specimens were investigated under static and dynamic compression, in the range of 1 ? 10-3 s-1 - 7 ? 103 s-1.  The fully dense specimens were fabricated using the Direct Metal Laser Sintering (DMLS?) process, and the tests results were compared to those of the same material made by conventional fabrication.  The porous specimens contained spherical pores with full control on the geometry and location of the pores.  Two types of specimens containing inner pores were fabricated.  In the first type, one pore is located at the geometric center of the specimen, with various volume fractions.  In the second type, two pores are located in various orientations and distances between the pores.  The geometry and locations of the pores was verified using X-ray imaging.  Specimens with one central pore were compared to specimens containing two pores with the same overall volume fraction.  The laser processed dense material exhibited superior strength in the static and dynamic tests, compared to the same conventional material, but the ductility of the two was comparable.  The single pore specimen exhibited a linear relationship between the load and the pore volume fraction.  The failure of the double pore specimens was strongly dependent on the pores’ orientation, while the distance between the pores was found to have a clear influence in only one specific direction (lateral).  The comparison between single and double pored specimens, at identical volume fractions, revealed the importance of the pores’ orientation with respect to the applied load.  Fractography of failed specimen showed the presence of shear localization at all strain rates.