Titanium Alloy Plates Research Articles

Nature of the adhesion bond between epoxy adhesive and titanium

The time dependence of the potential difference that appears between two VT6 titanium alloy plates separated by a mixture of epoxy resin with an epoxy hardener is studied. One of the plates is placed in epoxy resin until equilibrium is established, and the second plate is coated with an as-prepared mixture of epoxy resin and a hardener. It is found that the potential difference decreases in time because of charge transfer by Ti2+ ions through epoxy resin. Photoluminescence and infrared absorption spectra of epoxy adhesive on the VT6 alloy surface are recorded. Their analysis shows that the Ti2+ ions having penetrated into the as-prepared mixture of epoxy resin and a hardener interact with CN groups in adhesive molecules to form coordination compounds. As a result, a diffusion layer saturated with coordination compounds forms at the alloy/adhesive interface, which leads to an increase in the strength of the adhesive.

加工工艺及热处理对钛合金板材织构影响的研究现状

织构现象普遍存在于钛合金的生产加工过程中，并已成为钛合金加工方面的研究热点。本文从热轧、冷轧以及热处理制度三个方面分别介绍了近年来钛合金板材织构的研究概况，表明国内外钛合金板材织构研究的方向有较大的差异，而且国内对钛合金板材的织构研究仍较为粗浅，而国外的研究大部分为相变过程中的织构演变。 Texture is widespread in the production and the process of titanium alloy, which has become the focus of titanium alloy process research. This paper introduced the researches of titanium alloy plates’ texture in recent years respectively in terms of hot-rolling, cold-rolling and heat-treatment, which suggested that the research direction of titanium alloy plate texture has some differences at home and abroad. The domestic research on the texture of titanium alloy plate is still relatively shallow, while the foreign research mostly studies on the texture evolution in the process of phase transition.

Dynamic Analysis of the Titanium Alloy Plate under Thermal-acoustic Loadings

Hypersonic vehicles structures suffer complex combined loadings generally. For the thin-walled structures and thermal protection systems of the aircraft, high temperature and intensity acoustic loadings are the significant factors that leading to their break. The object of this paper is typical simply supported titanium alloy plate, the finite element method was adopted to calculate the critical thermal buckling temperature the ordinal coupling method and Newmark method were adopted to calculate the thermal- acoustic dynamic response. Based on the FEM analysis, the power spectrum densities (PSD) of center point was presented. Research results show that the thermal buckling of the typical simply supported titanium alloy plate occurs easily because of the low critical thermal buckling temperature, dynamic response of the thermal buckled plate suffering acoustic loads performs strong nonlinear characteristics and complex forms of exercise.

Characterization and Bone Differentiation of Nanoporous Structure Fabricated on Ti6Al4V Alloy

The optimal temperature for the alkaline treatment and subsequent heat treatment is determined to optimize the nanoporous structures formed on Ti6Al4V titanium alloy plates. Surface characterization of the alkali‐heat treated samples was performed by scanning electron microscopy, atomic force microscopy, X‐ray photoelectron spectroscopy, and X‐ray diffraction. The effects of heating temperatures on albumin adhesion, rat bone marrow mesenchymal stem cells (BMMSCs) adhesion, alkaline phosphatase activity, osteocalcin production, calcium deposition, and Runx2 mRNA expression were evaluated. The nanotopography, surface chemistry, and surface roughness were unchanged even after heat treatments at 200, 400, and 600°C. Only the amorphous sodium titanate phase changed, increasing with the temperature of the heat treatments, which played a crucial role in promoting superior cell adhesion on the nanoporous surface compared with the sodium hydrogen titanate obtained by a single alkali treatment. The heat treatment at 800°C did not enhance cell attachment on the surface because the nanostructure was dramatically destroyed with the reappearance of Al and V. This study reveals that nanoporous structures with amorphous sodium titanate were fabricated on Ti6Al4V surface through an amended alkali‐heat treatment process to improve BMMSCs adhesion.

Cladding of titanium and magnesium alloy plates using energy-controlled underwater three layer explosive welding

Titanium and magnesium alloy AZ31 plates were explosively welded using the underwater shock wave technique. A thin AZ31 interlayer was utilized as a proposed method to reduce kinetic energy loss and the formation of excessive molten zone at the interface. Through the experiments, the effects of initial inclined angle of the explosive, water distance and annealing of the AZ31 plates were investigated. Different experimental conditions allowed confirmation of the excessive molten zone, moderately welded zone and separation zone. Characterization of the welded interface suggests that bonding quality in the welded region showed planar interface without a molten zone. The effects of various welding parameters are discussed to evaluate moderate conditions of explosive welding. Welding conditions are discussed based on a weldability window estimated by numerically simulated dynamic bending angle at collision and horizontal collision point velocity, which may provide the kinetic energy lost by collision.

Laser Assisted Micro-Groove Ball Milling of Ti6Al4V

In micro scale, the size of cutting tool and shape significantly contributed to the machining performance. Many studies have been done to improve the cutting tool life and machined surface quality. Problems could become more severe when the workpiece has a low thermal conductivity while having high level of ductility such as titanium alloy. In this study, micro ball mill cutting tool is selected to produce a linear groove on a titanium alloy plate. The process is integrated with a laser source as a pre-heating element on the work piece surface. The condition of the flank surface of the tools and cutting force were observed and discussed. The influence of tool orientation and laser heating parameters in laser assisted micro ball milling (LAMM) were also discussed. It was found out that adhesion is the dominant tool wear mechanism thus fluctuate the cutting force value.

High-precision thickness setting models for titanium alloy plate cold rolling without tension

Due to its highly favorable physical and chemical properties, titanium and titanium alloy are widely used in a variety of industries. Because of the low output of a single batch, plate cold rolling without tension is the most common rolling production method for titanium alloy. This method is lack of on-line thickness closed-loop control, with carefully thickness setting models for precision. A set of high-precision thickness setting models are proposed to suit the production method. Because of frequent variations in rolling specification, a model structural for the combination of analytical models and statistical models is adopted to replace the traditional self-learning method. The deformation resistance and friction factor, the primary factors which affect model precision, are considered as the objectives of statistical modeling. Firstly, the coefficient fitting of deformation resistance analytical model based on over-determined equations set is adopted. Additionally, a support vector machine(SVM) is applied to the modeling of the deformation resistance and friction factor. The setting models are applied to a 1450 plate-coiling mill for titanium alloy plate rolling, and then thickness precision is found consistently to be within 3%, exceeding the precision of traditional setting models with a self-learning method based on a large number of stable rolling data. Excellent application performance is obtained. The proposed research provides a set of high-precision thickness setting models which are well adapted to the characteristics of titanium alloy plate cold rolling without tension.

Value of porous titanium alloy plates for chest wall reconstruction after resection of chest wall tumors.

To explore the value of porous titanium alloy plates for chest wall reconstruction after resection of chest wall tumors. A total of 8 patients with chest wall tumors admitted in our hospital from Jan. 2006 to Jan. 2009 were selected and underwent tumor resection, then chest wall repair and reconstruction with porous titanium alloy plates for massive chest wall defects. All patients completed surgery successfully with tumor resection-induced chest wall defects being 6.5 x 7 cm ~ 12 x 15.5 cm in size. Two weeks after chest wall reconstruction, only 1 patient had subcutaneous fluidify which healed itself after pressure bandaging following fluid drainage. Postoperative pathological reports showed 2 patients with costicartilage tumors, 1 with squamous cell carcinoma of lung, 1 with lung adeno-carcinoma, 1 with malignant lymphoma of chest wall, 2 with chest wall metastasis of breast cancers and 1 with chest wall neurofibrosarcoma. All patients had more than 2 ~ 5 years of follow-up, during which time 1 patient with breast cancer had surgical treatment due to local recurrence after 7 months and none had chest wall reconstruction associated complications. The mean survival time of patients with malignant tumors was (37.3 ± 5.67) months. Porous titanium alloy plates are safe and effective in the chest wall reconstruction after resection of chest tumors.

Internal residual stress measurement on linear friction welding of titanium alloy plates with contour method

The internal residual stress within a TC17 titanium alloy joint welded by linear friction welding (LFW) was measured by the contour method, which is a relatively new and destructive technique to obtain a full map of internal residual stress. The specimen was first cut into two parts; the out-of-plane displacement contour formed by the release of the residual stress was then measured; finally, taking the measured contour of the cut plane as the boundary conditions, a linear elastic finite element analysis was carried out to calculate the corresponding distribution of residual stress normal to the cut plane. The internal stress distribution of the TC17 titanium alloy LFW joint was also analyzed. The results show that the tensile residual stress in the TC17 LFW weld is mainly present within a region about 12 mm from the weld centerline; the peak tensile residual stress occurs at the weld centerline and reaches 360 MPa (about one third of the yield strength of TC17 alloy); within the weld zone of the TC17 LFW weld, the through-thickness stress is not uniform, and the internal stress is larger than that near the top or bottom surface.

Experimental investigation on the time-varying modal parameters of a trapezoidal plate in temperature-varying environments by subspace tracking-based method

Subspace-based methods for estimation of modal parameters are briefly reviewed in this study and a time-varying modal parameter identification algorithm, based on finite-data-window Projection Approximation Subspace Tracking, is presented to investigate the time-varying modal parameters of a trapezoidal titanium-alloy plate in temperature-varying environments. An experiment conducted on a steel beam with a removable mass is used to confirm the proposed method with a brief discussion on the factors of this method. Two groups of experiments are conducted to reveal the effects of varying temperature and heating speed on the natural frequencies of the plate, and the identified natural frequencies evidently show the effect of thermal stresses caused by temperature gradients in experiment.

Artificial Niches for Stromal Stem Cells as a Potential Instrument for the Design of the Surface of Biomimetic Osteogenic Materials

A relationship between the topography of rough calcium phosphate surfaces having osteogenic niche-reliefs and the electrostatic potential of these surfaces as a possible instrument to control stromal stem cells has been investigated. The in vitro culture of human lung prenatal stromal cells on nanostructured/ultrafine-grained VT1.0 titanium alloy plates with bilateral rough calcium phosphate (CaP) microarc coating was used. It was established that the amplitude of the electret CaP surface potential linearly increased with increasing area of valleys (sockets), and the negative charge is formed on the socket surface. The area of alkaline phosphatase staining (the marker of osteoblast maturation and differentiation) of adherent CD34 – CD44 + cells increases linearly with increasing area of artificial microterritory (socket) of the CaP surface occupied with each cell. The negative electret potential in valleys (sockets) of microarc CaP coatings can be the physical mechanism mediating the influence of the surface topography on osteogenic maturation and differentiation of cells in vitro. This mechanism can be called “niche-potential” and can be used as an instrument for biomimetic modification of smooth CaP surfaces to strengthen their integration with the bone tissue.

Low-grade myxofibrosarcoma following a metal implantation in femur: a case report

Myxofibrosarcoma is a myxoid variant of malignant fibrous histiocytoma that most commonly involves the extremities of elderly people. However, a primary myxofibrosarcoma with bone invasion in young adults is extremely rare. Herein, we report the case of a 31-year-old male with a gradually enlarging left thigh mass, who had a history of left femur fracture and received an open reduction and internal fixation with titanium alloy plates and screws 33 months previously. Imaging investigations revealed an irregularly shaped soft tissue mass around the left femur shaft and a partial bone defect in the middle one-third of the left femur. Pathological examination of the resected specimen showed a multi-nodular appearance, abundant myxoid matrix and elongated curvilinear capillaries. Immunohistochemical studies revealed that the tumor cells was positive for VIM and MDM2, and was negative for CK, MSA, SMA, DES, S-100 and CD34. Labeling index of Ki-67 was 25%. Based on the morphological finding and immunostaining, it was diagnosed as a low-grade myxofibrosarcoma. The clinical and imaging examinations did not reveal the evidence of a primary cancer elsewhere, and the patient had no personal or family history of malignancy. To our knowledge, this is the first case of a primary myxofibrosarcoma developed following a fracture and metal implantation in young adults.Virtual slidesThe virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1745984882113605

Morphology development of elongated α phases in hot working of large-scale titanium alloy plate

The role of subtransus hot working on microstructure morphology of TA15 titanium alloy plate with elongated α phases was studied by quantitative metallography on different sections. The results show that the microstructure morphology is mainly affected by loading direction. When the sample is compressed along normal direction, microstructure on the section vertical to normal direction has equiaxed primary α phase but microstructure on the section vertical to rolling direction has strip primary α phase with long axis along tangential direction. When the sample is compressed along rolling direction, microstructure on the section vertical to normal direction has strip primary α phase elongated along tangential direction but microstructure on the section vertical to rolling direction consists of strip and irregular broad-band primary α phase. The strip primary α phase aspect ratio is smaller at lower temperature due to the dynamic break-down of α phase. The difference on primary α phase aspect ratio between different sections decreases after compression along distinct directions in two loading passes, suggesting the improvement of equiaxity of primary α phase.

Investigation and Optimization of Laser Welding of Ti-6Al-4 V Titanium Alloy Plates

Titanium alloys are employed in a wide range of applications, from aerospace to medicine. In particular, Ti-6Al-4 V is the most common, thanks to an excellent combination of low density, high specific strength, and corrosion resistance. Laser welding has been increasingly considered as an alternative to traditional techniques to join titanium alloys. An increase in penetration depth and a reduction of possible welding defects are indeed achieved; moreover, a smaller grain size in the fused zone (FZ) is benefited in comparison to either tungsten inert gas (TIG) or plasma arc welding, thus improving the tensile strength of the welded structures. This study was carried out on 3 mm thick Ti-6Al-4 V plates in square butt welding configuration. The novelty element of the investigation is the use of a disk-laser source, which allows a number of benefits thanks to better beam quality; furthermore, a proper device was developed for bead protection, as titanium is prone to oxidation when in fused state. A three-level factorial plan was arranged in face-centered cubic scheme. The regression models were found for a number of crucial responses and the corresponding surfaces were discussed; then a numerical optimization was carried out. The suggested condition was evaluated to compare the actual responses to the predicted values; X-ray inspections, Vickers micro hardness tests, and tensile tests were performed for the optimum.

Analysis of micro-electrical discharge drilling characteristics in a thin plate of Ti–6Al–4 V

This paper presents a comprehensive study of the influence of machining parameters like voltage, capacitance, and threshold on various machining performances in micro-electrical discharge drilling (MEDD) process. The workpiece material was a 1.13-mm-thick plate of titanium alloy (Ti–6Al–4 V) while the tool was a 300-μm-diameter tungsten electrode. A full factorial design (33) was employed to carry out the experiment where each of the factors has three levels. Thus, mathematical models have been developed for the major performance indices like material removal rate, tool wear rate, wear ratio, overcut, and taper by multiple linear regression analysis. Also, response surface methodology has been employed to carry out multiple response optimization and to find the optimum process parameter settings to get a desired process yield by contour overlapping method. The proposed models could be considered as valuable tools for the process planning of MEDD leading to economical machining in industry.

Thermal Stress Variation of Titanium Alloy under Laser Radiation

Titanium alloy is a premium metal with properties of low density, high hardness and resistance against high temperature and corrosion, the application of which has gained serious explorations in manufacture and military. Laser pulses of different power, duration and beam spot size are employed under room temperature to investigate the thermal stress variation of a titanium alloy plate with the aim of proposing ideal coefficients in laser processing of titanium alloy. The experiment was carried out as numeric simulations of thermal response and thermal dynamo coupling of the titanium alloy plate by using the COMSOL software.

Joint properties of dissimilar Al6061-T6 aluminum alloy/Ti–6%Al–4%V titanium alloy by gas tungsten arc welding assisted hybrid friction stir welding

Hybrid friction stir butt welding of Al6061-T6 aluminum alloy plate to Ti–6%Al–4%V titanium alloy plate with satisfactory acceptable joint strength was successfully achieved using preceding gas tungsten arc welding (GTAW) preheating heat source of the Ti alloy plate surface. Hybrid friction stir welding (HFSW) joints were welded completely without any unwelded zone resulting from smooth material flow by equally distributed temperature both in Al alloy side and Ti alloy side using GTAW assistance for preheating the Ti alloy plate unlike friction stir welding (FSW) joints. The ultimate tensile strength was approximately 91% in HFSW welds by that of the Al alloy base metal, which was 24% higher than that of FSW welds without GTAW under same welding condition. Notably, it was found that elongation in HFSW welds increased significantly compared with that of FSW welds, which resulted in improved joint strength. The ductile fracture was the main fracture mode in tensile test of HFSW welds.

Preparation and characterization of multi-walled carbon nanotube/hydroxyapatite nanocomposite film dip coated on Ti–6Al–4V by sol–gel method for biomedical applications: An in vitro study

In the present research, the introduction of multi-walled carbon nanotubes (MWCNTs) into the hydroxyapatite (HA) matrix and dip coating of nanocomposite on titanium alloy (Ti–6Al–4V) plate was conducted in order to improve the performance of the HA-coated implant via the sol–gel method. The structural characterization and electron microscopy results confirmed well crystallized HA–MWCNT coating and homogenous dispersion of carbon nanotubes in the ceramic matrix at temperatures as low as 500°C. The evaluation of the mechanical properties of HA and HA/MWCNT composite coatings with different weight percentages of MWCNTs showed that the addition of low concentrations of MWCNTs (0.5 and 1wt.%) had improved effect on the mechanical properties of nanocomposite coatings. Moreover, this in vitro study ascertained the biocompatibility of the prepared sol–gel-derived HA/MWCNT composite coatings.

Cytocompatibility Comparative Study of Hydroxyapatite Coating on Titanium Alloy Treated with Two Chemical Routes

In order to prepare bioactive hydroxyapatite (Ca10 (PO4)6(OH) 2, HA) coating with ideal biocompatibility, the surface of titanium alloy was treated with the two kinds of chemical methods, which are the acid-alkali-combination method and Self-polymerization-adhesion of dopamine. After pretreatment, the treated titanium alloy plates were immersed in simulated body fluid (SBF) to form HA coating on their surface. The chemical composition of the coating was analyzed by an X-ray diffraction (XRD) and the morphology was observed by a scanning electron microscope (SEM). After that, the plates were training in vitro cytotoxicity test with MC3T3-E1 osteoblasts. Compared with the results of cell culture, the method of Self- polymerization -adhesion of dopamine showed better cell adhesion and proliferation..

Clinical Outcomes of Conversion Surgery from an External Fixator to an Iodine-Supported Titanium Alloy Plate

Background: External fixators brought a revolution in orthopaedic surgical treatment after the invention of distraction osteogenesis, which enabled treatment of various difficult diseases. However, they had some drawbacks, such as pin-site infections, psychological pain, and refracture after removal. To overcome these problems, many efforts have been made by shortening of the period of wearing them. One of those methods is conversion to locking plate, which had high risk of infection. To reduce the risk of infection, we performed conversion surgery using iodinesupported titanium plate (We named it iPlates, developed at our department). Questions/purposes: We therefore evaluated (1) Operation time, (2) whether bone union was achieved, (3) blood biochemistry, including thyroid hormone levels, (4) post-surgical complications. Patients and Methods: We assessed 28 legs. There were 13 legs after deformity correction and limb lengthening, three legs with pseudarthrosis after bone fracture, two legs after bone transport, one leg after shortening distraction, and one leg after open fracture. The mean follow-up period was 24.5 months. Results: Average operation time was 197 minutes. Bone union was achieved in all cases. Blood examinations did not find any abnormalities due to iImplant implantation, such as with thyroid hormones. One patient had superficial soft tissue infection treated with re-operation without removal of plate. Conclusions: An iPlate can reduce complications compare to previous studies. Conversion surgery with iPlate could be a new path for the future of external fixation.