Formability and mechanical properties of porous titanium produced by a moldless process

• Published in: Journal of biomedical materials research. Part B, Applied biomaterials Applied biomaterials, 2013-08, Vol.101B (6), p.1090-1094
• Main Authors: Naito, Yoshihito, Bae, Jiyoung, Tomotake, Yoritoki, Hamada, Kenichi, Asaoka, Kenzo, Ichikawa, Tetsuo
• Format: Article
• Language: English
• Subjects: Binders; Biocompatibility; Biocompatible Materials - chemistry; Biological and medical sciences; Compressive Strength; Dental Implants; Elastic Modulus; Formability; Humans; Materials Testing; Medical sciences; Metallurgy - methods; Modulus of elasticity; moldless process; Porosity; Prostheses and Implants; shrinkage; Sintering (powder metallurgy); strength; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Surgical implants; Technology. Biomaterials. Equipments; Titanium - chemistry; Titanium base alloys
• ISSN: 1552-4973; 1552-4981
• DOI: 10.1002/jbm.b.32919

Tailor‐made porous titanium implants show great promise in both orthopedic and dental applications. However, traditional powder metallurgical processes require a high‐cost mold, making them economically unviable for producing unique devices. In this study, a mixture of titanium powder and an inlay wax binder was developed for moldless forming and sintering. The formability of the mixture, the dimensional changes after sintering, and the physical and mechanical properties of the sintered porous titanium were evaluated. A 90:10 wt % mixture of Ti powder and wax binder was created manually at 70°C. After debindering, the specimen was sintered in Ar at 1100°C without any mold for 1, 5, and 10 h. The shrinkage, porosity, absorption ratio, bending and compressive strength, and elastic modulus were measured. The bending strength (135–356 MPa), compression strength (178–1226 MPa), and elastic modulus (24–54 GPa) increased with sintering time; the shrinkage also increased, whereas the porosity (from 37.1 to 29.7%) and absorption ratio decreased. The high formability of the binder/metal powder mixture presents a clear advantage for fabricating tailor‐made bone and hard tissue substitution units. Moreover, the sintered compacts showed high strength and an elastic modulus comparable to that of cortical bone. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2013.