Functionally graded Co-Cr-Mo coating on Ti-6Al-4V alloy structures.
Functionally graded, hard and wear-resistant Co-Cr-Mo alloy was coated on Ti-6Al-4V alloy with a metallurgically sound interface using Laser Engineering Net Shaping (LENS). The addition of the Co-Cr-Mo alloy onto the surface of Ti-6Al-4V alloy significantly increased the surface hardness without any intermetallic phases in the transition region. A 100% Co-Cr-Mo transition from Ti-6Al-4V was difficult to produce due to cracking. However, using optimized LENS processing parameters, crack-free coatings containing up to 86% Co-Cr-Mo were deposited on Ti-6Al-4V alloy with excellent reproducibility. Human osteoblast cells were cultured to test in vitro biocompatibility of the coatings. Based on in vitro biocompatibility, increasing the Co-Cr-Mo concentration in the coating reduced the live cell numbers after 14 days of culture on the coating compared with base Ti-6Al-4V alloy. However, coated samples always showed better bone cell proliferation than 100% Co-Cr-Mo alloy. Producing near net shape components with graded compositions using LENS could potentially be a viable route for manufacturing unitized structures for metal-on-metal prosthetic devices to minimize the wear-induced osteolysis and aseptic loosening that are significant problems in current implant design.
Vamsi Krishna
B
B
W.M. Keck Biomedical Materials Research Laboratory, School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164-2920, USA.
Xue
Weichang
W
Bose
Susmita
S
Bandyopadhyay
Amit
A
D000497:Alloys / Q000737:chemistry*; D002460:Cell Line; D002470:Cell Survival; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D006244:Hardness; D006801:Humans; D007834:Lasers; D010006:Osteoblasts / Q000166:cytology / Q000648:ultrastructure; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*; D014961:X-Ray Diffraction
D000497:Alloys; D020099:Coated Materials, Biocompatible; C031462:titanium alloy (TiAl6V4); D014025:Titanium