Advanced Materials Research Vols. 69-70

Abstract: This paper presents the optimization process of a surface roughness model for the milling 1Cr18Ni9Ti. The model is developed in term of milling speed, feed per tooth and radial depth of cut. Therefore, the regression model predicting formula for surface roughness has been established by means of uniform design of experiment, and then the response surface methodology was applied to generate response contours of surface roughness. The experimental results indicate that the material removal rate can be improved by selecting optimal milling parameters without increasing the surface roughness. Moreover, it is seen that the feed rate is the most significant factor on the surface roughness.

Abstract: TC11 is an α+β heat resistance titanium alloy with high strength to weight ratio, good corrosion resistance and high service temperature up to 500°C. Response Surface Methodology (RSM) is an empirical statistical modeling technique employed for multiple regression analysis using quantitative data obtained from properly designed experiments to solve multivariable equations simultaneously. In this paper, a series of experiments were carried out to evaluate the machinability of TC11 alloy based on RSM. Optimum results show feed rate at 0.05mm/r, depth of cut at 0.25mm and moderate cutting speed at 110.9m/min giving the satisfied machining quality.

Abstract: GH80A has been widely used in industry for its excellent property under high temperature. The surface integrity is one of the key factors that determine the lifetime. Hence, it’s worth to study surface topography and residual stress which are two important indexes used for evaluating the surface integrity. They are both resulted from the coupling of the mechanical and thermal effect during the turning which can not be well explained with experiment and numerical calculation. In this paper, workpiece surface topography was studied under different cutting parameters. The residual stress is measured and simulated to show more details about the effect of cutting parameters. The cutting temperature which is difficult to pick up in experiments is also simulated to explain the machining process.

Abstract: Stainless 2Cr13 is used as petroleum pipe material for its good performance in condition of high temperature, high pressure and corrosive environment. Buttress thread turning is a type of heavy machining, which has a great influence on the residual stress of workpiece. Residual stress is usually determined by cutting parameters and tool geometries. Experiments with different geometrical tools were carried out and a finite element model was used to study the influence of tool geometries on the residual stress. Experimental and simulated results showed that relatively bigger rake angle and smaller corner radius make a relatively lower tensile residual stress of workpiece surface in dry turning buttress thread.

Abstract: Research has been done on microstructure and machinability of two different free-cutting steels by using cutting tools coated and uncoated at the condition of different cutting parameters. The cutting force, surface quality, chip morphology and tool wear are investigated, which reveal the influence of the size and shape of sulphide inclusion on machinability. The experiment shows that the shape of spindled sulphide inclusion has relatively better machinability than stripped sulphide inclusion and the size of sulphide inclusion also plays some influence.

Abstract: In the paper, a new multilayer composition thin film thermocouple was developed, which can accurately measure the temperature nearby cutting edge in convenient and fast ways. By means of advanced Twinned microwave ECR plasma source enhanced Radio Frequency (RF) reaction non-balance magnetron sputtering technique, SiO2 insulating film, NiCr/NiSi sensor film and SiO2 protecting film were deposited on the surface HSS substrate. Both static calibration and dynamic calibration were completed. The results showed that the sensor had good performance, good linearity, quick dynamic response, response time constant was 12.7ms. The temperature near the cutting edge in cutting process of aluminum alloy was measured by the developed sensor. The bonding strength between multiple layer film and substrate of high-speed-steel met the presupposed demands.

Abstract: Contactless inductive power transfer system with conventional inductive technology was studied and a design method was presented after applying it to ultrasonic vibration machining systems. The compensation techniques are used for piezoelectricity transducer. Nodal plane support of transducer is researched and models of different structures for nodal plane support are got. Influence of rotary precision for different support due to centrifugal force and displacement vibration of nodal plane support to toolholder are analyzed. The system integrated with ultrasonic-vibration toolholder based on contactless inductive power transfer is designed. Power transfer and dynamic tests show that the design procedures and result based on theoretical analysis are comparative.

Abstract: The effects of the process parameters on the warpge and shrinkage of parts in different thickness are analyzed by Taguchi optimization method. Taguchi optimization method was used for exploiting mold analysis based on three level factorial designs. Orthogonal arrays of Taguchi, the signal-to-noise (S/N) ratio, the analysis of variance (ANOVA) are utilized to find the optimal levels and the effect of process parameters on warpage. It can be concluded that Taguchi method is suitable to solve the quality problem of the injection-molded thermoplastic parts.

Abstract: The designing of a micro turbine for micro gas turbine engine is presented in this paper. Micro power system is becoming more and more important for micro- and nano-scale system. The fast development of MEMS (Micro Electromechanical Systems) has strongly enhanced the application of new harder work materials. The fabrication of metallic 3D microstructures has been one of the most attractive topics of micro machining. Currently the basic materials of Micro-turbine Engineering were nonmetal materials such as SiC, most of them are 2D or quasi-3D structures. As a low cost, flexible, good repeatable machining process with negligible process forces, micro-EDM milling is well suited for freeform metallic micro structures. A three-dimensional micro turbine was fabricated by micro-EDM milling. A major problem in micro-EDM milling of complex 3D structure by using micro-electrode is the electrode wear. For reducing the impact of electrode wear, A new CAM system based on the UG software platform is developed in order to get good accuracy 2and higher efficiency. A simple tool path generation by CAD/CAM software and a general electrode wear compensation strategy is presented. The wear compensation can be apart from the design of CAD/CAM systems, so existing common CAD/CAM systems can be used to generate milling tool path with an unequal thickness lamination. And then post process for wear compensation and EDM milling can be done to modify tool path by adding wear compensation. The micro turbine blades of which the material is nickel alloy (GH4169) were successfully fabricated by using this strategy. The diameters of turbine are 2.8mm, and the height of each blade is 0.4mm.

Abstract: For the successful realization of product configuration design (PCD) in the condition of mass customization mode, the module encoding methods are studied. By analyzing the product structure model and the process of computer-aided PCD, all related information which is required for the module is decided. This paper proposes a scientific module encoding method suitable for PCD. It describes the geometric features of the modules, the interface relationships and the affiliations between modules. Further more, it introduces additional attribute codes used to evaluate product configuration. By this way the product information can be fully expressed in order to improve the efficiency of PCD.