Advanced Materials Research Vols. 139-141

Abstract: . A direct aspect of influencing giant magnetostrictive actuator's output performance is the driving magnetic field characteristics. Therefore, research on the influencing factors on the axial magnetic field distribution characteristics of giant magnetostrictive actuator is of great significance in the design. This paper analyzes the importance of the axial magnetic field distribution characteristics, analyzes the driving magnetic field using finite element method based on a designed giant magnetostrictive actuator, studies the affections of coil height, coil shape , magnetic block material, shell material , skeleton material, bottom cover material and output shaft material on the axial magnetic field distribution characteristics and reaches some conclusions about the influencing factors on the axial magnetic field distribution characteristics of giant magnetostrictive actuator. According to this paper, it provides the guidance for the optimization design of the driving magnetic field of the giant magnetostrictive actuator.

Abstract: An experimental investigation was carried out to understand the behavior of a powder metallurgy nickel-based superalloy when machined with sialon ceramic insert tools. Turning experiments were carried out at different cutting speeds and feed rates while depth of cut was kept constant. Cutting tool performance was evaluated with respect to temperature and cutting forces generated during turning, and tool wear. The sialon ceramic cutting tool showed high performance when increasing cutting speed, the machining experiments showed that sialon ceramic tools performed better at cutting speed up to 80 m/min. Abrasion and adhesion was the dominant wear mechanisms. Chipping on the tool rake and flank faces, as well as catastrophic failure under thermal shock and mechanical loading, was also observed in experiments. As cutting temperature was very high when turning powder metallurgy nickel-based superalloy, good high-temperature strength and thermal shock resistance were indispensable to the cutting tools for machinging this kind of material.

Abstract: The paper studies machining technology, cutting parameter. It does experimentation research for drilling superfine deep-hole drilling of 2Cr13 stainless steel, of which slenderness ratio is greater than 300.The test result indicates that the drilling process is stable and reliable, the optimizing cutting technology and cutting parameters is rational, the production of the type of deep hole drilling technical problems have been solved. It has practical application in common production. The parameter can produce superfine deep holes of 2Cr13 stainless steel with the length to diameter ratio 322. In this paper, the key technologies of drilling 2Cr13 stainless steel deep hole are explained, which include selecting the system of drilling deep hole, designing of structure of deep hole bit, selecting the material of cutter blade of bit , and designing the geometry parameters of blade.

Abstract: According to the traditional tooth profile, modification process cannot meet the traction gear’s technical requirements of the high-speed locomotive. A new way for the tooth profile modification technology was provided in the paper. The slotting profile modification process was proposed, the formulating methods of the tooth profile modification K diagram was introduced, modification curve fit as the sections of involutes, the modification profile angles of slotting cutter corresponding sections of involutes was deduced using the profile angle error analysis theory and the tooth profile of modification slotting cutter precision was designed. The feasibility and advantages of modification slotting cutter were validated by examples, which indicates the widely use of this technology in high-speed locomotive traction gear.

Abstract: The detritus of drilling well carry the important information of stratum, which is the important basis for discovering and evaluating oil and gas layer. So it is important to get detritus from the viscous drilling mud. In this paper, it studies the technology of cleaning detritus. According to the requirements of cleaning process and water - saving on the drilling well spot, DF - Windspout separator cleaner is designed, which is used to clean detritus. The mixture of viscous drilling mud and the detritus are accelerated through the double fluid (DF) system. Then they go into the windspout separation, they are separated to fluid and solid at here. Next the fluid is purified by ultrasonic microfiltration plant. The water can be recycled again. It can ensure the clean debris, the accuracy of collecting debris, accurate, remove the fake block and solves the lack of the dis - continuity of sampling.

Abstract: The profile of cycloid-arc screw compressor rotors is not a smooth profile, and it has a tip on it. When designing the hob cutter is used for machining this kind of rotors, the profile of hob edge will appear separation. In this paper, the design theory of hob cutter for hobbing the no-symmetric cycloid-arc rotor with tip profile is researched, and the best way for design this kind of hob cutter with a separate edge is attained according to practical design, manufacture and test. Its results are shown that it is good practice to design the hob cutter and hob the cycloid-arc rotor. Thus, the machining method for hobbing screw compressor can enhance high productivity and machining accuracy.

Abstract: Present work of this paper focus on developing a milling force model according to the characteristic of the matching of lengthened shrink-fit holder (LSFH) and cutter using back propagation neural network (BPNN). Time parameter is taken as a factor of the input vector besides 6 processing conditions which mainly affect the milling force, and then the forecasting of 3D transient milling forces are achieved. A lot of milling experiments were performed to get training and testing samples and a Matlab program was designed to evaluate and optimize the network. The test experiments show that the forecasting results are well agreed with the experimental results and the errors of 3D force components are less than 0.18. Besides an extended performance, the BPNN model has higher efficiency and higher accuracy than the customary analytical model.

Abstract: γ-titanium aluminide are considered as a potential light weight material. γ-titanium aluminide alloy has the advantages of high temperature resistance, high performance of anti-oxidation effect, low-density, high specific strength and rigidity etc. This material is suitable to be applied in aeronautics, astronautics and automobile industry. But high hardness, brittleness and mechanical strength make it hard to process. This problem is more acute in deep hole drilling. In this paper, we have analyzed the cutting performance of γ- titanium aluminide and designed a deep-hole drill with three different tool materials. The experimental result shows: (1) YG8 cemented carbide is the appropriate tool material for drilling γ-titanium aluminide. (2) Small rake angle of external edge (γo=-1°) and big clearance angle of external edge (αo=10~12°) should be chosen. (3) Best wear results are obtained when oil is utilized as cutting fluid.

Abstract: High Speed Milling (HSM) is well known as an innovative key technology for modern machining. HSM can obtain very high surface qualities, subsequent manually finishing operations can be eliminated in many cases totally or at least partially. Theoretical and experimental researches have proven that the cutting force in a high speed milling process has significant influences both on surface roughness and deflection of the cutting tool. In this paper, mould steel for high speed milling experiments by multi-factor test on the high speed milling machine tools. By studying the relation of overhang length, cutting speed and cutting force of cutting parameters, the cutting force tested is analyzed in high speed milling. When mold steel is cut at high speed, the influence of cutting speed on cutting force is studied, which has a guidance in the actual production.

Abstract: In order to analyze the feature of high-load and high-stiffness gas bearing with tapered recess, the complete gas field consisting of supply hole and clearance is built up, and a laminar flow model and a sectional turbulent-laminar flow model are respectively applied to calculate the pressure distribution of centrally-fed gas bearing with tapered recess in different clearances. The theoretical results agree in general with the experimental. The experimental result demonstrates its high load, however its big gas cavity. On the above basis a circular ring gas supply bearing with tapered recess is presented, the calculation result shows that for this new type of ring inlet bearing the pressure drop in entrance area will be reduced effectively even with smaller tapered recess height, and compared with centrally-fed gas bearing with tapered recess, its gas recess volume decreased and stability increased, while the load capacity is basically the same.