Experimental and numerical studies of titanium foil/steel explosively welded clad plate

Ti/Fe clad plate had attracted extensive attention because of its important application. In order to reduce the titanium layer thickness, the explosive welding of TA1 titanium foil to Q235 steel plate was carried out. The interfacial bonding performance was analyzed by micromorphology analysis and mechanical property test, and the formation process of interfacial wave and molten block in the vortex was simulated by smoothed particle hydrodynamics(SPH) method. The results showed that salt as pressure transfer layer used in explosive welding could play a good buffer effect on the collision between flyer and base layers. Regular waveforms were formed on the bonding interface, and the titanium foil/steel clad plate exhibited good welding quality and bonding property. The crest of the observed interfacial wave moved 200 μm from the beginning to the final formation, and it was important of jet on the formation of interfacial waveform. The interface was mainly bonded in the form of molten layer, and the grains near the interface were streamlined. Molten block containing intermetallic compounds and metal oxides appeared in the vortex of wave crest.

CLINICAL COMPARISION OF THE TREATMENT OF CERVICAL PROLAPSE OF INTERVERTEBRAL DISC BY USING CAGE OR TITANIUM PLATE

Objective To compare the clinical effects of treating cervical prolapse of intervertebral disc by using Solis cage, titanium cage and autogenous iliac crest graft (AICG) combined with titanium plate. Methods 64 cases of cervical prolapse of intervertebral disc were analyzed retrospectively. All the patients were followed up for about one year. Group A is composed of 20 patients (30 intervertebral spaces) treated with microdiscectomy and Solis cage fusion; group B is composed of 21 patients(22 intervertebral spaces) treated with titanium cage and group C is involved of 23 patients(28 intervertebral spaces) which were dealt with AICG combined with titanium plate. The differences in the total X ray exposure time, time working on iliac bone, incidence of complications, fusion rate, incidence of JOA score recovery rate more than 50% and rehabilitation time of the three groups are analyzed. Results All indexes from group A and B were more satisfactory than those from group C (P<0.05). The statistic analysis results of the incidence of complications of cervical part, rehabilitation time in group A are 5.0±1.8, 5.1±1.2; and that is 14.3±2.6, 7.5 ±1.6 and 26.1±6.2, 8.6±2.3 in group B and group C respectively. There is significant difference between group A and group B on the incidence of complications of cervical part and rehabilitation time (P<0.05). Results of the incidence of JOA score recovery rate >50% in group A(95.8±3.2) was more satisfactory than that in group B(93.6±2.9), while there was no statistical difference between group A and group B (P>0.05). Conclusion The Solis cage is better in treating the cervical prolapse of intervertebral disc than other ways. Also, it makes the operation easier, rehabilitation time shorter, and it causes fewer complications.

Study on the interface of direct hot rolling titanium-clad steel plates

In this study,the interface characteristics of a direct hot rolling titanium-clad steel plate were analyzed, and the mechanism of interface cracking was explored. The detrimental effect from the formation of TiFe ,TiC,and a Si-enriched layer on the bonding strength was clarified, and an industrial-scaled titanium-clad steel plate with shear strength over 200 MPa was produced with a carefully set schedule accordingly. It was found that hot rolling titanium-clad steel plates had a flat interface without obvious cracks. In the rolling process,both Ti and Fe atoms interdiflhsed,but Fe difthsed much faster than Ti. The Fe-diffused area consisted of three regions. After a high temperature heat treatment, the diffusion depth of Fe and Ti elements increased significantly and evident Si segregation and TiFe layers were identified. Thermal cracking initiated in the Si segregation layer and then propagated along the TiFe layer and Fe-diffused layer on the titanium side.

Application of anterior decompression and reconstruction using titanium mesh with locking plates in the management of cervical spondylotic myelopathy

Objective：To observe the clinical effect of anterior decompression and reconstruction using titanium mesh with locking plates in the treatment of cervical spondylotic myelopathy. Methods：One hundred and twenty patients with cervical spondylotic myelopathy were treated by anterior decompression and reconstruction using titanium mesh with locking plates. There were 66 men and 54 women ranges in age from 37 to 72 Years（mean age, 58.3 years）. The mean Japanese orthopedic surgery association（JOA） scale was 9.6 points before operation. Patients were followed up clinically and radiographically. Results：Having stood surgery well, the operation time ranged between 60-100 min and bleeding during operation ranged between 20-200 ml. There were no case of postoperative infection, recurrent laryngeal nerve palsy, or esophageal or tracheal laceration or rupture. The average follow-up period was 14.3 months（range, 12 to 24 months） in 96 who were followed up. At the last follow-up visit the mean JOA scale had improved to 14.4 points, reflecting an improvement of 4.8 points. The results were considered to be excellent in 87 patients, good in 25, fair in 6, and poor in 2. No hardware-related complications or adjacent segment degenerative changes were encountered during the follow-up periods. Stable bone union was observed in all cases and the average time required for fusion was 5.7 months. Conclusion：Titanium mesh filled with autologous bone graft can avoid the complications associated with harvesting bone from the iliac crest donor site. When combined with cervical anterior locking plate, it can obtain satisfatory clinical results for the treatment of cervical spondylotic myelopathy.

Evaluation of Oxidation of Ti-Al and Ti-Al-Cr Coatings Arc-ion Plated on Ti-60 High-temperature Titanium Alloy

High-temperature titanium alloy for aeroengine compressor applications suffers from high-temperature oxidation and environmental corrosion, which prohibits long-term service of this kind alloy at temperatures above 600℃. In an attempt to tackle this problem, Ti-48Al （at. pct） and Ti-48Al-12Cr （at. pct） protective coatings were plated on the substrate of alloy Ti-60 by arc ion plating （ALP） method. Isothermal and cyclic oxidation tests were performed in static air at elevated temperatures. Phase composition, morphology of the coatings and distribution of elements were investigated by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and energy dispersive X-ray analysis （EDX）. The results showed that the Ti-48Al coating exhibited good isothermal oxidation resistance during exposure at 800℃, but poorer resistance against oxidation at 900℃. By contrast Ti-48Al-12Cr coating demonstrated excellent isothermal oxidation resistance at both temperatures. Cyclic oxidation tests performed at 800℃ indicated that resistance and no spallation of coatings was observed. But both coatings demonstrated good cyclic oxidation at 900℃ only Ti-48Al-12Cr coating demonstrated excellent cyclic oxidation resistance.

Design and test of a protective structure for the double vertical explosive welding of large titanium/steel plate

A comprehensive protective structure with rigidity and flexibility was put forward and designed in view of the quality and safety problems for the double vertical explosive welding of large titanium/steel cladding plate.The movement speed and displacement of the protective structure was calculated by establishing its physics model.The dynamics and stabilization properties were analyzed,and the protective structure parameters were optimized and devised.The comprehensive protective structure,which is composed of rigidity unit and flexibility wall,can bear the impact of detonation wave and the high-speed movement of the cladding plate.There are no damage and deformation in the protective structure and the cladding plate.The protective structure can be used many times.The bonding rate of the Ti/steel plate obtained was nearly 100%,and there is no deformation,surface cracks,and big wave and micro-defects.Therefore,the protective problems of the double vertical explosive welding can be solved effectively by the protective structure.

SEM observation of bone interface of titanium-coated 317L plate screw

The scanning electron microscope (SEM) results of bone interface of titanium-coated 317L plate screw are reported in this article. 317L plate screw had a rough surface composed of sprayed pure titanium which formed a bone/metal interface in biointegration after implanted into the mandible of dog. Though a bone/metal interface in osseointegration was also formed on the surface of uncoated 317L plate screw after implantation, a smal1 space was seen between the bone and surface of the screw, indicating that the tissue compatibility of titanium-coated 317L plate screw may be better than that of the non-coated screw.

Effect of interface morphology on the mechanical properties of titanium clad steel plates

Interface morphology has important influence on the bond quality of titanium clad steel plates. The mechanical properties of titanium clad steel plates with wavy and straight interfaces were investigated by tensile-shear tests and bending tests. The interface morphology of the plates was examined by optical microscopy （OM） and scanning electron microscopy （SEM）. The experimental results show that the shear strength of a wavy interface is higher than that of a straight interface. A wavy interface is the guarantee for obtaining high shear strength to provide a greater shear resistance. During the maerobending process, cracks appear in the swirl of the wave tip and ferrotitanium intermetallies. For in-situ observing the bending process by SEM, the wave tip of a wavy interface and the massive ferrotitartium intermetallies of a straight interface are places where cracks initiate and propagate. The results are the same as those observed in the macrobending process. Became of high hardness, the wave tip and the massive ferrotitanium intermetallies are hard in terms of compatible deformation.

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.

无界域上具有记忆的非自治Plate方程随机吸引子的存在性

研究无界域上一类具有衰退记忆和加性噪声的非自治Plate方程解的长时间行为.利用一致估计验证了解的拉回渐近紧性,获得了其随机吸引子的存在性.

Numerical simulation and welding stress and distortion control of titanium alloy thin plate

Trailing peening technology is adopted to control the welding stress and distortion of titanium alloy thin plate. With the nonlinear finite element theory and analyzing software Marc, normal welding process and trailing peening welding process of titanium alloy thin plate are simulated, separately. In the process of simulation, the Gauss heat source is adopted under the condition of arc welding and the relatively accurate results are obtained. In addition, the experimental results of TC4 titanium alloy thin plate in the conventional welding and the trailing peening welding processes are obtained. The results of simulation and experiment shows that the trailing peening technology can reduce the welding residual stress obviously and the welding distortion can be controlled effectively.

Surface Modification of Titanium Plate with Anodic Oxidation and Its Application in Bone Growth

Using implants for dental applications are well-accepted procedures as one of the solutions for periodontal defect repair. Suitable design and materials, their reaction with the surrounding hard tissues and interfacial biomechanical properties are still considered to be the primary criteria which need to be addressed. The purpose of present study was to evaluate the bone repair around pure titanium implants and porous surface using anodic oxidation technique, after their insertion in tibiae of rats (n = 15). Five animals received pure titanium-surface implants in tibia, 5 rough-surface implants (TiO2/Ti) in tibia and last five acted as control group. The interfacial integrity and compositional variation along the interface were studied using scanning electron microscope (SEM) with energy dispersive analysis of X-ray (EDX) and histopathology after 2 months. The rats were sacrificed 8 weeks after surgery and fragments of the tibiae containing the implants were submitted to histological analyses to evaluate new bone formation at the implant-bone interface as well as the tibiae were radio graphed. The SEM-EDX results confirmed the initial stability for the Ti implant, but the regeneration of new bone formation was faster in the case of TiO2/Ti implant, and hence could be used for faster healing. The results of the histological analysis showed that osseointegration occurred for both types of implants with similar quality of bone tissue. In conclusion, the porous-surface implants contributed to the osseointegration because they provide a larger contact area with surface roughness at implant-bone interface can help into the formation of physico-chemical bondage with the surrounding hard tissues.

Exact solution for thermal vibration of multi-directional functionally graded porous plates submerged in fluid medium

An analytical method for analyzing the thermal vibration of multi-directional functionally graded porous rectangular plates in fluid media with novel porosity patterns is developed in this study.Mechanical properties of MFG porous plates change according to the length,width,and thickness directions for various materials and the porosity distribution which can be widely applied in many fields of engineering and defence technology.Especially,new porous rules that depend on spatial coordinates and grading indexes are proposed in the present work.Applying Hamilton's principle and the refined higher-order shear deformation plate theory,the governing equation of motion of an MFG porous rectangular plate in a fluid medium(the fluid-plate system)is obtained.The fluid velocity potential is derived from the boundary conditions of the fluid-plate system and is used to compute the extra mass.The GalerkinVlasov solution is used to solve and give natural frequencies of MFG porous plates with various boundary conditions in a fluid medium.The validity and reliability of the suggested method are confirmed by comparing numerical results of the present work with those from available works in the literature.The effects of different parameters on the thermal vibration response of MFG porous rectangular plates are studied in detail.These findings demonstrate that the behavior of the structure within a liquid medium differs significantly from that within a vacuum medium.Thereby,they offer appropriate operational approaches for the structure when employed in various mediums.

Scanning Electron Microscopy (SEM) Analysis and Hardness of Diffusion Bonded Titanium-Titanium and Titanium-Copper Plates with Static Force and without Interlayers

In the present research, commercially pure Ti (grade-2) has been diffusion bonded with Ti and Cu plate under static force without any interlayers. The diffusion bonded samples were tested for micro hardness and micro structural analysis through optical microscopy and SEM. It is found from the present investigation that the bonded zone is affected by the processing variables such as bonding time (1 - 2 h), bonding force (250 N), bonding temperature (973 - 1073 K) and surface roughness. Results of the investigation revealed that temperature range of ?973 - 1073 K along with time duration of 1 - 2 hours in vacuum has resulted in a joint having high hardness with minimum pores. Hardness of the bond depends on the grain boundary diffusion at the interface and maximum hardness was achieved in the case of Ti-Cu joints. When Ti-Cu plates were used for bonding at 973 K for 2 hours, Cu-Ti solid solution along with a zone of different intermetallics was formed in the bonded zone. However, at higher temperatures, no continuous zone of intermetallics was found in the bonded region but instead Ti-Cu solid solution appeared.

An Orthogonal Collision Dynamic Mechanism of Wave-Like Uplift Plateaus in Southern Asia

In southern Asia, there are three large-scale wave-like mountains ranging from the Tibetan Plateau westward to the Iranian Plateau and the Armenian Plateau. On the southern side between plateaus, there are the Indian Peninsula and the Arabian Peninsula. What dynamic mechanisms form the directional alignment of the three plateaus with the two peninsulas remains a mystery. In the early stages of the Earth’s geological evolution, the internal structure of the Earth was that the center was a solid core, and the outmost layer was a thin equatorial crust zone separated by two thick pristine continents in polar areas, while the middle part was a deep magma fluid layer. Within the magma fluid layer, thermal and dynamic differences triggered planetary-scale vertical magma cells and led to the core-magma angular momentum exchange. When the core loses angular momentum and the magma layer gains angular momentum, the movement of upper magma fluids to the east and the tropical convergence zone (TCZ) drives the split and drift of two thick pristine continents, eventually forming the current combination of these plateaus and peninsulas and their wave-like arrangement along the east-west direction. Among them, the horizontal orthogonal convergence (collision) of upper magma fluids from the two hemispheres excited the vertical shear stress along the magma TCZ, which is the dynamic mechanism of mountain uplifts on the north side and plate subductions on the south side. To confirm this mechanism, two examples of low-level winds are used to calculate the correspondence between cyclone/anticyclonic systems generated by the orthogonal collision of airflows along the atmospheric TCZ and satellite-observed cloud systems. Such comparison can help us revisit the geological history of continental drift and orogeny.

Unsteady MHD Casson Nanofluid Flow Past an Exponentially Accelerated Vertical Plate:An Analytical Strategy

In this study,the characteristics of heat transfer on an unsteady magnetohydrodynamic(MHD)Casson nanofluid over an exponentially accelerated vertical porous plate with rotating effects were investigated.The flow was driven by the combined effects of the magnetic field,heat radiation,heat source/sink and chemical reaction.Copper oxide(CuO)and titanium oxide(TiO2)are acknowledged as nanoparticle materials.The nondimensional governing equations were subjected to the Laplace transformation technique to derive closed-form solutions.Graphical representations are provided to analyze how changes in physical parameters,such as the magnetic field,heat radiation,heat source/sink and chemical reaction,affect the velocity,temperature and concentration profiles.The computed values of skin friction,heat and mass transfer rates at the surface were tabulated for various sets of input parameters.It is perceived that there is a drop in temperature due to the rise in the heat source/sink and the Prandtl number.It should be noted that a boost in the thermal radiation parameter prompts an increase in temperature.An increase in the Prandtl number,heat source/sink parameter,time and a decrease in the thermal radiation parameter result in an increase in theNusselt number.The computed values of the skin friction,heat andmass transfer rates at the surface were tabulated for various values of the flow parameters.The present results were compared with those of previously published studies andwere found to be in excellent agreement.This research has practical applications in areas such as drug delivery,thermal medicine and cancer treatment.

Imaging plate scanners calibration and the attenuation behavior of imaging plate signals

Based on previously reported work, we propose a new method for calibrating image plate(IP) scanners, offering greater flexibility and convenience, which can be extended to the calibration tasks of various scanner models. This method was applied to calibrate the sensitivity of a GE Typhoon FLA 7000 scanner. Additionally, we performed a calibration of the spontaneous signal attenuation behavior for BAS-MS, BAS-SR, and BAS-TR type IPs under the 20±1°C environmental conditions, and observed significant signal carrier diffusion behavior in BAS-MS IP. The calibration results lay a foundation for further research on the interaction between ultra-short, ultra-intense lasers and matter.

Modeling Geometrically Nonlinear FG Plates: A Fast and Accurate Alternative to IGA Method Based on Deep Learning

Isogeometric analysis (IGA) is known to showadvanced features compared to traditional finite element approaches.Using IGA one may accurately obtain the geometrically nonlinear bending behavior of plates with functionalgrading (FG). However, the procedure is usually complex and often is time-consuming. We thus put forward adeep learning method to model the geometrically nonlinear bending behavior of FG plates, bypassing the complexIGA simulation process. A long bidirectional short-term memory (BLSTM) recurrent neural network is trainedusing the load and gradient index as inputs and the displacement responses as outputs. The nonlinear relationshipbetween the outputs and the inputs is constructed usingmachine learning so that the displacements can be directlyestimated by the deep learning network. To provide enough training data, we use S-FSDT Von-Karman IGA andobtain the displacement responses for different loads and gradient indexes. Results show that the recognition erroris low, and demonstrate the feasibility of deep learning technique as a fast and accurate alternative to IGA formodeling the geometrically nonlinear bending behavior of FG plates.

The interaction between a shaped charge jet and a single moving plate

Reactive armour is a very efficient add-on armour against shaped charge threats.Explosive reactive armour consists of one or several plates that are accelerated by an explosive.Similar but less violent acceleration of plates can also be achieved in a completely inert reactive armour.To be efficient against elongated jets,the motion of the plates needs to be inclined against the jet such that a sliding contact between the jet and the plates is established.This sliding contact causes a deflection and thinning of the jet.Under certain circumstances,the contact will become unstable,leading to severe disturbances on the jet.These disturbances will drastically reduce the jet penetration performance and it is therefore of interest to study the conditions that leads to an unstable contact.Previous studies on the interaction between shaped charge jets and flyer plates have shown that it is mainly the forward moving plate in an explosive reactive armour that is effective in disturbing the jet.This is usually attributed to the higher plate-to-jet mass flux ratio involved in the collision of the forward moving plate compared to the backward moving plate.For slow moving plates,as occurs in inert reactive armour,the difference in mass flux for the forward and backward moving plate is much lesser,and it is therefore of interest to study if other factors than the mass flux influences on the protection capability.In this work,experiments have been performed where a plate is accelerated along its length,interacting with a shaped charge jet that is fired at an oblique angle to the plate’s normal,either against or along the plate’s velocity.The arrangement corresponds to a jet interacting with a flyer plate from a reactive armour,with the exception that the collision velocity is the same for both types of obliquities in these experiments.The experiments show that disturbances on the jet are different in the two cases even though the collision velocities are the same.Numerical simulations of the interaction support the observation.The difference is attributed to the character of the contact pressure in the interaction region.For a backward moving plate,the maximum contact pressure is obtained at the beginning of the interaction zone and the contact pressure is therefore higher upstream than downstream of the jet while the opposite is true for a forward moving plate.A negative interface pressure gradient with respect to the jet motion results in a more stable flow than a positive,which means that the jet-plate contact is more stable for a backward moving plate than for a forward moving plate.A forward moving plate is thus more effective in disturbing the jet than a backward moving plate,not only because of the higher jet to plate mass flux ratio but also because of the character of the contact with the jet.