The Atmospheric plasma spraying method (APS) is one of most used methods for deposition on layers with different thickness on surfaces with different degrees of complexity. This paper presents a new concept of thermal...
详细信息
ISBN:
(纸本)9781634394321
The Atmospheric plasma spraying method (APS) is one of most used methods for deposition on layers with different thickness on surfaces with different degrees of complexity. This paper presents a new concept of thermal barrier coating for the prevention of delaminating of the sprayed layer and this consists of an adherent layer of Ni Mo Al (90-5-5) and a top coat of Al2O3-TiO2, deposited by atmospheric plasma spraying (APS) on specimens of nodular cast iron of which the camshaft are made of the internal combustion engine The samples studied in this paper were obtained by thermal spray using an atmospheric plasma spray installation SPRAYWIZARD - 9MCE. To highlight results, SEM (Scanning Electron Microscopy) analyses were performed using a Quanta 200 3D Microscope Dual Beam. Using x-ray analysis it was possible to detect the existing phases and constituents in the layer deposited with the plasma spray method and comparisons were made about the composition of the used powders. Testing adhesion and cohesion of the coating by the "scratch" was made with micro tribometer UMTR 2M-CTR.
The use of robots in performing various surgical procedures have seen a rapid increase in the last couple of decades, where advantages such as increased accuracy and repeatability can be realized. These systems still ...
详细信息
ISBN:
(纸本)9781467353199
The use of robots in performing various surgical procedures have seen a rapid increase in the last couple of decades, where advantages such as increased accuracy and repeatability can be realized. These systems still have various factors limiting their wide spread use, including; large costs, taking up too much space, and providing little or no force-feedback. Accurate force-feedback is not only important in providing the sense of touch to the surgeon, but also in safety and automation related procedures, and is the main focus of this paper. Specifically the interaction forces between the surgical tool and the manipulated tissues are of interest, with all other forces eliminated or compensated for. This paper introduces a robotic system for minimally invasive surgery with a novel surgical tool for force/torque sensing. The tool uses an overcoat method to eliminate force/torque corruption at the trocar, and an accelerometer for gravity compensation. The overcoat method is briefly presented, where the developed approach for gravity compensation and calibration is discussed in detail. Simulation and experimental results are presented to validate the concepts and show the successful removal of gravitational forces with good accuracies.
Ceramics and ceramic materials are materials with promising technical applications and with relatively high characteristics in terms of mechanical strength, but at the same time very low properties due to the fragilit...
详细信息
ISBN:
(纸本)9781634394321
Ceramics and ceramic materials are materials with promising technical applications and with relatively high characteristics in terms of mechanical strength, but at the same time very low properties due to the fragility and the cracks appearing in the cooling layer. The cracking resistance is important not only for the technical products which operates in the mechanical thermal loads domain but also for structural components, cracks of which fragility is unacceptable even in arbitrary *** this paper its being revealed a new concept of TBC with an exfoliation prevention of the sprayed layer and it consists in an adherent layer of NiMoAl (90-5-5) sprayed through an electric arc and a top coat of ZrO2/20%Y2O3, deposited by atmospheric plasma spraying (APS) on specimens of Ni base superalloy, of which the aircraft turbine blades are made. There were made some attempts of spraying at different distances, namely: 100 mm respectively 110 mm. These samples had been then subjected to mechanical bending tests to observe adhesion to the substrate. Highlighting and interpretation of structural changes caused by the tests carried out have been made using modern methods of structural analysis.
The method of plasma spraying for obtaining superficial layers with special properties has begun to be increasingly used in industry. In this paper are described and presented a series of layers experimentally obtaine...
详细信息
ISBN:
(纸本)9781634394321
The method of plasma spraying for obtaining superficial layers with special properties has begun to be increasingly used in industry. In this paper are described and presented a series of layers experimentally obtained, using powders of WC-Co type on different substrates (steel and Ni alloy) in order to observe the influence of the substrate on the interface and the characteristics of the deposited layer. The attention was paid to the layers that must meet the hardening requirements of the steam inlet borders in the rotor blades network of the low-pressure body of the steam turbines. The analyzed samples were obtained by thermal spraying, using an atmospheric plasma spray installation type SPRAYWIZARD - 9MCE. To highlight the results were performed analyses of scanning electron microscopy (electron microscope type QUANTA 200 3D DUAL BEAM) and X-Ray diffraction (diffractometer X'PERT PRO MRD) for determining the phases and constituents from the deposited layer.
The improvement of the temperature resistance of the aircraft engine elements can be obtained by application of a ceramic coating, single layer (TBC) or several composite layers. Turbine blades are made of a super all...
详细信息
ISBN:
(纸本)9781634394321
The improvement of the temperature resistance of the aircraft engine elements can be obtained by application of a ceramic coating, single layer (TBC) or several composite layers. Turbine blades are made of a super alloy that has a maximum operating temperature of close to 1000°C, the idea of using ceramic materials was foreseen. To increase thermal resistance of engine the elements requires, apart from laboratory investigations, also numerical study of the different aero-engine parts. For aircraft engine the most important are turbine blades, where high temperatures and stress concentrations during thermal shocks or t hermal fatigue can be observed during engine exploitation. The present paper deals with the solution of the transient temperature transfer problem in bare and thermal barrier coated alloy Inconel 625 for the temperature range up to 1000 °C. The computational fluid dynamics (CFD) part of analysis was performed by application of ANSYS Fluent code receiving the temperature field of combustion gas.
Analytical techniques are presented for the motion planning and control of a 10 degree-of-freedom biped walking robot. From the Denavit-Hartenberg method and Newton-Euler equations, joint torques are obtained in terms...
详细信息
Analytical techniques are presented for the motion planning and control of a 10 degree-of-freedom biped walking robot. From the Denavit-Hartenberg method and Newton-Euler equations, joint torques are obtained in terms of joint trajectories and the inverse dynamics are developed for both the single-support and double-support cases. Physical admissibility of the biped trajectory is characterized in terms of the equivalent force-moment and zero-moment point. This methodology has been used to obtain stability of walking biped robot Archie developed in IHRT. A simulation example illustrates the application of the techniques to plan the forward-walking trajectory of the biped robot.
The majority of visual SLAM techniques utilize interest points as landmarks. Therefore, they suffer from two main problems;scalability and data association reliability. Recently, there has been increasing interest in ...
详细信息
Monocular depth has been found using estimation, closed-form solution and learning techniques. Estimation and closed-form solution compute the depth from motion, while learning techniques calculate the depth using a s...
详细信息
This article focuses on the dynamic index and performance of a radial symmetric six-legged *** first the structure of the robot is described in brief and its inverse kinematics is *** the dynamic model is formulated a...
详细信息
This article focuses on the dynamic index and performance of a radial symmetric six-legged *** first the structure of the robot is described in brief and its inverse kinematics is *** the dynamic model is formulated as based on the Lagrange equations.A novel index of total torque is proposed by considering the posture of the supporting *** new index can be used to optimize the leg's structure and operation for consuming minimum power and avoiding unstable postures of the robot.A characterization of the proposed six-legged robot is obtained by a parametric analysis of robot performance through simulation using the presented dynamic *** influences are outlined as well as the usefulness of the proposed performance index.
We present the fabrication of 3D porous micro-channel for artificial capillary blood vessel model to study the pressure of glomerulus in vitro. The 3D porous micro-channel was fabricated by direct laser writing to mim...
详细信息
ISBN:
(纸本)9781479914951
We present the fabrication of 3D porous micro-channel for artificial capillary blood vessel model to study the pressure of glomerulus in vitro. The 3D porous micro-channel was fabricated by direct laser writing to mimic the complex structure of capillary blood vessel. It was designed to connect with micro-channels which were fabricated by UV lithography process. The 3D porous micro-channel was made of IP-L to represent the glomerulus structures via direct laser writing. The fabricated structure was observed by optical and electron microscope to reveal the fabrication errors due to shrinkage. Optimization of the direct laser writing method shows that IP-L is a better photoresist compare to Ormocomp for 3D porous micro-channel by solid model fabrication. The PDMS micro-channel has also been fabricated and assembled on the glass with the IP-L porous micro-channel. There was no leakage when fluid flow experiment was performed due to surface tension.
暂无评论