| Title |
Damping Capacity and Fracture Toughness of Over-aged Ti-6Al-4V Biomaterials |
| Authors |
이동근(Dong Geun Lee); 이성학(Sung Hak Lee); 이용태(Yong Tai Lee); 염종택(Jong Taek Yeom); 김정한(Jeoung Han Kim); 박노광(Nho Kwang Park) |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
Ti-6Al-4V alloy; α2-Ti3Al precipitates; Widmanstatten; equiaxed; Bimodal; damping capacity; impulse-frequency response method; fracture toughness |
| Abstract |
The present study was concerned with the effects of over-aging on damping property and fracture toughness in Ti-6Al-4V alloy for biomaterials. Damping property and toughness become important factors for titanium implants, which have big modulus difference between bone and implant, and need high damping capacity for bone-implant compatability. Widmanstatten, equiaxed, and bimodal microstructures containing fine α2 particles were obtained by over-aging a Ti-6Al-4V alloy. Over-aging heat treatment was conducted for 200 hrs at 545℃. Fracture toughness, Charpy impact and bending vibration tests were conducted on the unaged and the over-aged six microstructures, respectively. Charpy absorption energy and apparent fracture toughness decreased as over-aging was done, even if the materials were strengthened by precipitation of very fine and strong α2-Ti3Al particles. On the other hand, damping properties were enhanced by over-aging in Widmanstatten and equiaxed microstructures, but was weakened in bimodal microstructure due to the softening of tempered martensite and the decreasing of elastic difference between tempered martensite and α phase contained α2 particles, etc. These data can provide effective information to future work about internal damping and fracture properties of Ti-6Al-4V biomaterials. |