title: Microstructure and mechanical properties of open-cellular biomaterials prototypes for total knee replacement implants fabricated by electron beam melting.
abstract: Total knee replacement implants consisting of a Co-29Cr-6Mo alloy femoral component and a Ti-6Al-4V tibial component are the basis for the additive manufacturing of novel solid, mesh, and foam monoliths using electron beam melting (EBM). Ti-6Al-4V solid prototype microstructures were primarily α-phase acicular platelets while the mesh and foam structures were characterized by α(')-martensite with some residual α. The Co-29Cr-6Mo containing 0.22% C formed columnar (directional) Cr(23)C(6) carbides spaced ~2 μm in the build direction, while HIP-annealed Co-Cr alloy exhibited an intrinsic stacking fault microstructure. A log-log plot of relative stiffness versus relative density for Ti-6Al-4V and Co-29Cr-6Mo open-cellular mesh and foams resulted in a fitted line with a nearly ideal slope, n = 2.1. A stress shielding design graph constructed from these data permitted mesh and foam implant prototypes to be fabricated for compatible bone stiffness.
authors.affiliation: Department of Metallurgical and Materials Engineering, The University of Texas at El Paso, El Paso, TX 79968, USA. lemurr@utep.edu
authors.forename: L E
authors.initials: LE
authors.lastname: Murr
authors.forename: K N
authors.initials: KN
authors.lastname: Amato
authors.forename: S J
authors.initials: SJ
authors.lastname: Li
authors.forename: Y X
authors.initials: YX
authors.lastname: Tian
authors.forename: X Y
authors.initials: XY
authors.lastname: Cheng
authors.forename: S M
authors.initials: SM
authors.lastname: Gaytan
authors.forename: E
authors.initials: E
authors.lastname: Martinez
authors.forename: P W
authors.initials: PW
authors.lastname: Shindo
authors.forename: F
authors.initials: F
authors.lastname: Medina
authors.forename: R B
authors.initials: RB
authors.lastname: Wicker
mesh_terms: D000497:Alloys / Q000737:chemistry; D019645:Arthroplasty, Replacement, Knee; D001672:Biocompatible Materials / Q000737:chemistry*; D055119:Elastic Modulus; D004583:Electrons; D055595:Mechanical Phenomena; D008855:Microscopy, Electron, Scanning; D008958:Models, Molecular; D008968:Molecular Conformation; D055620:Optical Phenomena; D019736:Prostheses and Implants; D011474:Prosthesis Design / Q000379:methods*; D012984:Software; D014961:X-Ray Diffraction
chemical_list: D000497:Alloys; D001672:Biocompatible Materials