A Sheep Model for the Osseointegration of PEO-treated Gamma Titanium Aluminide

A sheep model was used to study the osseointegration of gamma titanium aluminide (γTiAl) screws subjected to plasma electrolytic oxidation (PEO). The degree of osseointegration was determined by measuring the maximum torque for screw removal from bone after 3 and 6 months of implant placement in sheep for PEO-treated γTiAl, untreated γTiAl, and untreated Ti6Al4V cortical screws. The amount of bone growth and mineralization were qualitatively observed by von Kossa staining of the bone tissue in the region surrounding the implants. Inductive Coupled Plasma-Optical Emission Spectroscopy (ICP-OES) was carried out to determine trace amounts of metallic elements in blood serum samples obtained from the animals. Generally Al, Cr and V were present in blood serum in comparable quantities in the control and implanted animals, while neither Ti nor Nb was detected. Results from histological analysis and SEM images indicated that de novo bone growth occurred to a greater extent for the PEO treated γTiAl screws. Furthermore, the torque for screw removal from bone was significantly higher (p<0.05) for the PEO-treated γTiAl implants. Taken together, the data supports that the PEO surface treatment enhanced osseointegration to a considerable degree indicating the potential for favorably utilizing PEO-treated γTiAl for dental and orthopedic implant applications.

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Limitations of an Indentation Model for Grinding Gamma Titanium Aluminide

Dynamic Systems and Control ◽

10.1115/imece2002-32038 ◽

2002 ◽

Author(s):

H. Ali Razavi ◽

Steven Danyluk ◽

Thomas R. Kurfess

Keyword(s):

Force Control ◽

Titanium Aluminide ◽

Normal Force ◽

Removal Rate ◽

Cubic Boron Nitride ◽

Normal Component ◽

Grinding Force ◽

Cutting Depth ◽

Gamma Titanium Aluminide ◽

Gamma Titanium

This paper explores the limitations of a previously reported indentation model that correlated the depth of plastic deformation and the normal component of the grinding force. The indentation model for grinding is studied using force control grinding of gamma titanium aluminide (TiAl-γ). Reciprocating surface grinding is carried out for a range of normal force 15–90 N, a cutting depth of 20–40 μm and removal rate of 1–9 mm3/sec using diamond, cubic boron nitride (CBN) and aluminum oxide (Al2O3) abrasives. The experimental data show that the indentation model for grinding is a valid approximation when the normal component of grinding force exceeds some value that is abrasive dependent.

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The Dependence of Tensile Ductility on Investment Casting Parameters in Gamma Titanium Aluminides

MRS Proceedings ◽

10.1557/proc-552-kk2.1.1 ◽

1998 ◽

Vol 552 ◽

Author(s):

R. Raban ◽

L. L. ◽

T. M.

Keyword(s):

Titanium Aluminide ◽

Titanium Aluminides ◽

Tensile Ductility ◽

Gamma Titanium Aluminide ◽

Cooling Rates ◽

Gamma Titanium ◽

Investment Cast ◽

Thermal Data ◽

Titanium Aluminide Alloys ◽

Simulation Package

ABSTRACTPlates of three gamma titanium aluminide alloys have been investment cast with a wide variety of casting conditions designed to influence cooling rates. These alloys include Ti-48Al-2Cr-2Nb, Ti- 47Al-2Cr-2Nb+0.5at%B and Ti-45Al-2Cr-2Nb+0.9at%B. Cooling rates have been estimated with the use of thermal data from casting experiments, along with the UES ProCAST simulation package. Variations in cooling rate significantly influenced the microstructure and tensile properties of all three alloys.

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