Advanced Materials Research Vols. 690-693

Abstract: It's very important to control the sensors of ultrasonic and Time Domain Reflectometry when study the relationship between gas hydrate saturation and acoustic parameters in sediments. We combined Ultrasonic Wave and Time Domain Reflectometry in one apparatus to study the acoustic parameters of gas hydrate-bearing sediments in different saturation. The experimental results show that the apparatus is well designed and can work smoothly. Subsequently, we compare the calculated data by time-average equation, Woods equation, Lees weighted equation and Biot-Gassmann Theory by Lee (BGTL) with the observed data in experiments. It suggests that the Lees weighted equation and BGTL are more applicable in our experiments and various sediments.

Abstract: In this paper X-ray and penetrant inspection were applied to detect flaws in welding zone between diamond segment and matrix in order to detect position and form of the flaw. The result can be used to assess weld quality and performance of diamond saw blade. The result shows that main flaws on welding zone are crack, incomplete fusion, lack of fusion, pore. These flaws can affect the life and machining precision of the diamond saw blade. We can improve the welding process to ensure welding quality and reliability of saw blade by detected flaws.

Abstract: It has been one of the difficulties that high-precision thin hole is machined. The supersonic vibration reaming acoustic system is installed in the lathe. The supersonic wave energy applies to reamer to create pulse power on the cutting process. The separating vibration cutting is achieved to make the pulse force. The tests on reaming surface quality and precision are carried. The quality of surface and accuracy machined by this method is more than that by grinding. The reaming process is stability. The cutting force is greatly reduced. The cutting temperature is at room temperature. The tool life is greatly increased. Surface quality and shape precision is greatly improved. The regulations of the ultrasonic vibration reaming thin hole in hardened steel are also summarized. The test results show that the ultrasonic vibration reaming by reamer is of very superior cutting mechanism. It is efficient cutting methods for high-precision thin-hole machining of hardened materials.

Abstract: As the final process in manufacturing of plastic-container pump assemblies, a kind of personal care goods, in a company, the exterior of the products is currently inspected by manual work. In this processes, defections such as existence of oil stain, discoloration and incomplete forming or assembling are examined. The product quality from such manual process is mainly dependent on the experience of workers, thus consistent quality between products is not guaranteed. To cope with such problem, this study develops an automation system for the exterior inspection of the product, and the performance of the system manufactured is evaluated through a series of operation experiments. Also, the system is modified twice through statistical analysis to enhance its performance.

Abstract: Wire spinning, which is a deformation process of great complexity in laying head pipe, was simulated using MSC. Marc, a software for finite element analysis, with the aid of production data collected in a high-speed wire spinning production line. The stress condition and the temperature distribution of the laying head inner wall, under the condition of high speed dry sliding friction, were obtained. The effects of different feed speeds on the contact stress and the transient temperature of the easily-wear part were analyzed. The simulation result coincides with the actual wear condition in the laying head pipe, indicating the soundness of the finite element model and making a contribution to optimizing the special curve of the laying head pipe and the finished rolling speed.

Abstract: The influence functions action orientation of the Bonnet Polishing (BP) process is perpendicular to the contact zone. So the normal error of the aspheric surface should be used as the residual error to calculate the dwell time. But the Z axis direction error is generally adopted as the residual error and few papers on the normal error have been reported hitherto. Its necessary to pay attention to this issue. In this paper, two algorithms which are Asphericity Subtraction (AS) algorithm and Z Axis Direction Error Transformation (ZADET) algorithm are presented to calculate the normal error of the large aspheric surface. Simulations in three different cases are organized to utilize these two algorithms, together with the comparison of them. And the comparison of the normal error and the Z axis direction error is also organized. Its found that there exists difference between AS algorithm and ZADET algorithm. Both of them can be used to calculate the normal error of the aspheric surface when the ratio value of the width to radius is small. And the difference between the normal error and Z axis direction error is considerable. So the normal error should be used as the residual error to calculate the dwell time in BP process.

Abstract: Different types of WC/NiCrBSi metal matrix composite coatings were deposited by laser cladding. The wear resistance of these composite coatings was tested with a ring-on-disc (MMG-10) apparatus. The morphologies of the worn surfaces were observed using a scanning electron microscopy (SEM) equipped with an energy dispersive spectroscopy (EDS) for elemental composition. The results showed that the wear resistance of the laser clad WC/Ni-based composite coatings increased significantly with increasing WC mass fraction. It had also been suggested that the composite coating containing 60 wt% agglomerate WC had superior wear resistance property. The wear mechanism was then discussed on the basis of microscopic observations of the worn surfaces.

Abstract: The numerical simulation method of LCRM Using Coaxial Inside-Beam Powder Feeding is put forward in this page. LCRM conduction model is established, the life and death unit to be used to simulate the real laser cladding process. Calculation results show that the molten pool temperature will gradually increase with the number of cladding layers increase; the highest temperature at the point of application of the laser beam position later; in the cladding process, cooling rate is great in high temperature period, and in low temperature section, cooling rate relatively slight.

Abstract: Artificial neural networks were introduced in the area of laser milling. The prediction model of surface quality in laser milling parts, including the width, depth of cladding layer, was proposed based on the back propagation (BP) neural networks. The model combined the global optimization searching performance of the genetic algorithm and the localization of the back propagation (BP) neural networks. Five technical parameters were selected to test the reliability of the model. The simulation and experimental results show that the evolutionary neural network based on genetic algorithm can effectively overcome the problem of falling into local minimum point. This method can get higher accuracy of prediction. It improves the measurement precision with the maximum relative error 2. 21% between the predicted content and the real value.

Abstract: Ti-6Al-4V alloy samples were deposited by laser solid forming from blended 90wt%Ti+6wt%Al+4wt%V powders and from pre-alloyed Ti-6Al-4V powders under the same processing parameters, and the geometric properties of the deposited samples were studied comparatively. It was found that the height and the width of the deposited layers increased with the increase of the laser power and the decrease of the laser scanning velocity. Meanwhile, the height and the width of the deposited layer obtained from blended elemental powders are much higher than that from pre-alloyed powders. The mixing enthalpy for Ti-6Al-4V was calculated by using the Miedema model and the Toop model, and it was found that the alloying process for Ti, Al and V in the molten pool is exothermic, which is responsible for the higher deposited layer height and width of LSF Ti-6Al-4V from blended elemental powders due to the higher energy in the molten pool and the higher temperature of the molten pool.