Advanced Materials Research Vols. 433-440

Abstract: In this paper results of manufacturing tests are described done in order to evaluate the performances of twist drills of diameter d = 1.2 mm and 1.4 mm respectively, if boring into stainless steel X90CrMoV18 (1.4112). Deep-hole drilling was realized thus, that the depth of the bore hole was greater than 10 times the diameter of the twist drill (L/d >10). In order to reduce the impact on the environment caused by the coolant, it was found that minimum quantity lubrication (MQL) can be applied. Hence, the ecology of the mass production of perforated discs for the food processing industry can be improved. The performance of the several small diameter twist drills was determined and evaluated by, firstly, their deep-hole drilling capability, e.g. assessed by the variation or even increase of cutting forces with increasing depth and travel, whether the forces exceed a critical level due to poor chip extraction. In addition, the suitability to use or rather implement the different small diameter twist drills for high-speed cutting (HSC) and finally the individual tool service life for each investigated twist drill. This research project has shown that the accomplishable performance and operating time are strongly dependent on tool cutting material and the tool geometry, especially the size of the chip flutes of a twist drill, as well as the individual coating of the cutting tools.

Abstract: How to effectively reduce spread is an important subject in the area of ring rolling. In the paper, a reliable coupled thermo-mechanical three-dimensional (3D) finite element (FE) model for hot rolling of large rings is developed. The relationship between spread and the equivalent shape parameters of the deformation zone is discussed. Variations of spread with relative reduction Rr during hot rolling of titanium alloy large rings with different sizes are analyzed and compared using FE simulation. The main results reveal that (1) the spread in a ring exhibits an axisymmetric distribution after the first revolution of the ring. (2) the peak spread appears in the inside or outside layer of a ring, and the minimum spread is found in the middle layer. (2) as Rr increases, the spread increases and the end-plane quality of the ring reduces.

Abstract: For hot ring rolling of large parts, rolling force and moment are of significance for designing, choosing and optimizing of rolling die and mill. In the study, the average shape parameter of the deformation zone of ring rolling is presented first, and then a reliable coupled thermo-mechanical three-dimensional (3D) finite element (FE) model for the process is developed. Finally, the influences of geometric factors on rolling force and moment during hot ring rolling of titanium alloy large parts are explored. The main results show that increasing the ratio of driver roll radius to idle roll radius or decreasing the average radius of blank is beneficial to a saving of rolling force and moment, while the axial height of blank has a little influence.

Abstract: The thermal property of the high-speed spindle system in vertical machining center was studied by using finite element method ( FEM ). When the spindle runs at the speed of 4300r/min, the system reaches the thermal steady state after 17 minutes, the temperature distribution in the spindle was symmetrical, and the highest temperature is in the inner ring the front bearing, with temperature rise of 36.7 .With the cutting force as load, The calculated result was taken as an input parameter in Abaqus software, the results of which show the thermal deformation of the spindle. The maximum thermal deformation of the spindle is 1.185 × 10^-2 mm, on the shoulder, near the edge of the cutter.

Abstract: Fe-Ni-Mo-C-Cr system powder metallurgy in the as-sintered was investigated on pin-on-rolling wear tester for their dry sliding wear behavior. The morphology of worn surfaces and wear mechanism were analysed by SEM. Results show the hot-forging deformation quenching and tempered considerably decreased the porosity and improved wear resistance, and compare with quenching microstructure, tempered microstructure has high wear resistance and match of strength-toughness. Fe-2.0Ni-0.4Mo-0.5C-0.6Cr alloy presented best wear characteristics. SEM observations of the worn surface revealed microploughing and plastic deformation and crack were the basic dry sliding wear morphology,and oxidative wear and delamination wear are dominant wear mechanism.

Abstract: Wireless networks today can be divided into several phases, the first voice communication is based, that is 1g, the second phase, where we are in stage-based data traffic. In the third phase, will be mainly dominated by video, the need for new ways to optimize the network in order to prevent saturation. The future is 4G era. Now, based on 3G mobile communication technology has been successful in the global implementation of standardized and up. 4G standards battle has been engaged in fierce. For now it seems 3G technology in the WiMAX and LTE will be strong competitors in the future 4G standards. In this paper, we will talk about the 4G technology standard, WiMAX and LTE the basic characteristics of the key aspects of technology and application prospects of WiMAX and compare LTE and the development of future wireless networks.

Abstract: This paper presents a study about split drag flaps as control surfaces to generate yawing motion of a blended wing body aircraft. These flaps are attached on UiTM’s Blended Wing Body (BWB) Unmanned Aerial Vehicle (UAV) Baseline-II E-4. Deflection of split drag flaps on one side of the wing will produce asymmetric drag force and, as consequences, yawing moment will be produced. The yawing moment produced will rotate the nose of the BWB toward the wing with deflected split drag flaps. The study has been carried out using Computational Fluid Dynamics to obtain aerodynamics data with respect to various sideslip angles (ß). The simulation is running at 0.1 Mach number or about 35 m/s. Results in terms of dimensionless coefficient such as drag coefficient (C_D), side force coefficient (C_S) and yawing moment coefficient (C_n) are used to observe the effects of split drag Subscript text flaps on the yawing moment. All the results obtained shows linear trends for all curves with respect to sideslip angles (ß).

Abstract: To ascertain the optimal reserve of the professional relief workers in China, the author defines and optimizes the reserve cycle of the professional relief workers in this paper. Based on the analysis of the optimal personnel reserve in a single cycle, the author gains the short-term and long-term security personnel reserves as well as the relevant optimal personnel reserves, and then analyzes and introduces the factors to influence the optimal reserve and the corresponding adjustment methods.

Abstract: This article describes the vehicle based on virtual instrument engine control system research and development of the experimental platform. Virtual instrument technology combined with artificial intelligence inference mechanism for the establishment of a virtual instrument based on the engine electronic control system testing and fault diagnosis system, to achieve the electronic control engine system sensors online test, waveform analysis, data storage, replay and failure diagnosis.

Abstract: Seal leakage in medicinal high-speed grinder is one of the problems probe and research by equipment designer and user. In this paper, a new structure of seal is designed with a combination of micro-nano magnetic fluid seal and mechanical lubricating ring. Sealing structure has been optimized through tests on the reliability. Experimental results show that the method can better solve the seal leakage in Medicinal high-speed grinder.