Abstract: COMTES FHT has been active in a field of research and development of high-strength wires for quite some time. The main material was pure titanium. The primary goal of this effort is to develop a continuous production process for ultrafine and nanostructured materials with the aid of severe plastic deformation (SPD). This article outlines mechanical and microstructural properties of the materials and the options available for testing the components made of these materials. Ti Grade 2 and Grade 4 wires are the key products of interest. Ti Grade 2 with ultrafine to nano-sized grain shows ultimate strength of up to 1050 MPa. Ti Grade 4 reaches ultimate strengths of up to 1250 MPa. These values are twice or three times as higher as those found in the unprocessed material. For those fields of medicine where implantable metallic materials are used, bulk ultrafine to nanostructured titanium is available. It is manufactured by SPD techniques. These processes leave the chemical properties of the initial material unchanged but markedly improve its final mechanical properties, in particular, the strength. Ultrafine to nanostructured titanium retains all the significant and, from the biological viewpoint, desirable properties that are important for its use in medicine, i.e. those properties which made pure titanium the preferred material also for dental implants.
Abstract: In this study, Ti-5Al-2.5Fe alloy was prepared by powder metallurgy. The elemental titanium, aluminum, and iron powders were mechanically alloyed for 10 h in a vacuum atmosphere. A stainless steel jar and stainless steel balls were used for mechanical alloying. The alloyed powders were then sintered by vacuum hot pressing at 950 °C for a soaking time of 30 minutes. Pure titanium was also sintered at the same conditions for comparison of mechanical properties and microstructural behavior. The samples were investigated by scanning electron microscopy, XRD analysis, and optical microscopy. Results showed that, after mechanical alloying, a homogeneous distribution of the elements was obtained, and desired a-b structure was determined. Ti-5Al-2.5Fe alloy was successfully produced, and the alloy showed enhanced mechanical properties compared to the commercial pure titanium.
Abstract: Titanium and its alloys have been used extensively over the past 25 years as biomedical materials in orthopedic and dental applications because of their good mechanical properties, corrosion resistance, and biocompatibility. It is known that the surface properties of titanium implants can enhance the cellular response and play an important role in Osseo integration. The rate and quality of Osseo integration in titanium implants are related to their surface properties. The purpose of this investigation was to evaluate the effect of sandblasting and acid etching on surface morphology, roughness, the wettability of titanium. The surface properties will be characterized by scanning electron microscopy and contact angle and roughness measurements. The results show that surface morphology, roughness, and wettability were changed and enhanced by these treatments.
Abstract: The pullout strength had an effect on the stability of
plate screw fixation when inserted in the cervical spine. Nine
different titanium alloy bone screws were used to test the pullout
strength through finite element analysis. The result showed that the
Moss Miami I can bear the highest pullout force at 1,075 N, which
causes the maximum von Mises stress at 858.87 MPa, a value over
the yield strength of titanium. The bone screw should have large
outer diameter, core diameter and proximal root radius to increase the
pullout strength.
Abstract: Calcium phosphate coating (CaP) has been employed
for protein delivery, but the typical direct protein adsorption on the
coating led to low incorporation content and fast release of the
protein from the coating. By using bovine serum albumin (BSA) as a
model protein, rapid biomimetic co-precipitation between calcium
phosphate and BSA was employed to control the distribution of BSA
within calcium phosphate coating during biomimetic formation on
titanium surface for only 6 h at 50oC in an accelerated calcium
phosphate solution. As a result, the amount of BSA incorporation and
release duration could be increased by using a rapid biomimetic coprecipitation
technique. Up to 43 fold increases in the BSA
incorporation content and the increase from 6 h to more than 360 h in
release duration compared to typical direct adsorption technique were
observed depending on the initial BSA concentration used during coprecipitation
(1, 10 and 100 μg.ml-1). From x-ray diffraction and
Fourier transform infrared spectroscopy studies, the coating
composition was not altered with the incorporation of BSA by this
rapid biomimetic co-precipitation and mainly comprised octacalcium
phosphate and hydroxyapatite. However, the microstructure of
calcium phosphate crystals changed from straight, plate-like units to
curved, plate-like units with increasing BSA content.
Abstract: This study investigated the combined effect of cold rolling and heat treatment on the mechanical properties of Al-Ti alloy. Samples of the alloy are cast in metal mould to obtain 0.94-2.19wt% mixes of titanium. These samples are grouped into untreated (as-cast) and those that are cold rolled to fifty percent reduction, homogenized at 5000C and soaked for one hour. The cold rolled and heat treated samples are normalized (RTn) and quench-tempered (RTq-t) at 1000C. All these samples are subjected to tensile, micro-hardness and microstructural evaluation. Results show remarkable improvement in the mechanical properties of the cold rolled and heat treated samples compared to the as-cast. In particular, the RTq-t samples containing titanium in the range of 1.7-2.2% demonstrates improve tensile strength by 24.7%, yield strength, 28%, elastic modulus, 38.3% and micro-hardness, 20.5%. The Al3Ti phase being the most stable precipitate in the α-Al matrix appears to have been responsible for the significant improvement in the alloy’s mechanical properties. It is concluded that quench and temper heat treatment is an effective method of improving the strength-strain ratio of cold rolled Al-.0.9-2.2%Ti alloy.