title: Effect of nano-hydroxyapatite reinforcement in mechanically alloyed NiTi composites for biomedical implant.
abstract: Equi-atomic NiTi alloy composites reinforced with 0, 2, 4 and 6vol.% nano-hydroxyapatite (HA) were successfully synthesized using pressureless sintering. Pure Ni and Ti elements were ball milled for 10h in order to produce a mechanically alloyed equi-atomic NiTi alloy (MA-NiTi). Mechanically alloyed NiTi and HA powders were blended, compacted and then sintered for 3h at 1325K. The sintered density varied inversely with volume percent of HA reinforcement. The X-Ray diffraction spectra and SEM images showed the formation of multiple phases like NiTi, NiTi2, Ni3Ti, and Ni4Ti3. The back scattered-SEM image analysis confirmed the presence of Ni-rich and Ti-rich phases with increasing HA content. The 6vol.% HA reinforced composite showed Ni3Ti as the major phase having the highest hardness value which can be attributed to the presence of relatively harder phases along with higher HA content as a reinforcement. The composite of MA-NiTi with 2vol.% HA manifested the most desirable results in the form of better sintering density mainly due to the minute decomposition of NiTi into other phases. Therefore, the 2vol.% reinforced MA-NiTi composite can be exploited as a novel material for manufacturing biomedical implants.
authors: Faculty of Materials and Chemical Engineering, GIK Institute of Engineering Sciences and Technology, Topi 23640, Pakistan. Electronic address: muhammad.akmal@giki.edu.pk.
authors: Muhammad
authors: M
authors: Akmal
authors: Faculty of Materials and Chemical Engineering, GIK Institute of Engineering Sciences and Technology, Topi 23640, Pakistan. Electronic address: ahmadrazac@yahoo.com.
authors: Ahmad
authors: A
authors: Raza
authors: Faculty of Materials and Chemical Engineering, GIK Institute of Engineering Sciences and Technology, Topi 23640, Pakistan.
authors: Muhammad Mudasser
authors: MM
authors: Khan
authors: Faculty of Materials and Chemical Engineering, GIK Institute of Engineering Sciences and Technology, Topi 23640, Pakistan.
authors: M Imran
authors: MI
authors: Khan
authors: Department of Chemical Engineering, Kangwon National University, Samcheok, 25913, Republic of Korea.
authors: Muhammad Asif
authors: MA
authors: Hussain
mesh_terms: D000497:Alloys / Q000737:chemistry*; D017886:Durapatite / Q000737:chemistry*; D020007:Implants, Experimental; D053761:Nanocomposites / Q000737:chemistry*; D009532:Nickel / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*
chemical_list: D000497:Alloys; D009532:Nickel; D017886:Durapatite; D014025:Titanium
keywords: Biomedical implants; Hydroxyapatite; Mechanically alloyed NiTi; NiTi-HA composites