Applied Mechanics and Materials Vols. 268-270

Abstract: The application of a fluorine-containing water and oil repellent to cotton and polyester/cotton fabrics was investigated. The influence of dosage of the water and oil repellent, curing temperature and time, and pH of application on water and oil repellencies was discussed to determine the optimized finishing process. In addition, some physical properties of finished fabrics were tested. The results showed that the two fabrics finished with the fluorine-containing water and oil repellent at a low dosage exhibited good water and oil repellencies, and the inherent quality of the fabrics had not been adversely affected.

Abstract: A new method for determination of friction coefficient in sheet metal forming of Mg alloy AZ31B is presented in this paper. The method is based on the bulging test of sheet metal in which the specimen is processed with a hole at the center. The diameter of the hole will increase along the stroke of the punch and the dimensional change of the hole has a certain relationship with the friction coefficient at the punch/specimen interface. Thus, the friction coefficient can be determined indirectly according to the dimension of the hole in the bulging process. The bulging process of the sheet is simulated using FE code DEFORM-2D. The analysis model is set up according to the experiment of the bulging and the friction calibration curves are generated from the simulations of the bulging by setting different coefficients of friction. The friction coefficient can be determined by measuring the hole dimension during the bulging process and comparing it with the friction calibration curves.

Abstract: Swiss-type lathe is the machine tool of choice in machining titanium dental implants. It is able to do turning, drilling, and milling in a single setup. One of the more challenging processes is the internal threading at one end of the dental implants. Threading in titanium at as little as M1.4 and as deep as 6mm possesses certain difficulties in terms of chips disposal, BUE, tool wear, and tool breakage. The study focuses on internal threading whirling. A new method of applying cutting fluid jet has been tested. The experiments have been done by using the Swiss-type lathe, Star SR-20R.

Abstract: Served as polymer flooding for the enhanced oil recovery, partially hydrolyzed polyacrylamide (PAM) has widely been employed for the oil production. The PAM solution prepared by the ground clean water was characterized with a higher viscosity in the early years while one, made by the oilfield produced water in the existence of complicated constituents, features a worse viscosity in the recent operation. In the practical opinion, the viscosity is an important indicator of the polymer flooding. The high viscosity of aqueous PAM solution has being pursued for a goal of the successful operation. For the reason, this research objective could be set toward seeking the causes of the viscosity degradation. In this paper, specific ions in the preparing water on effects of the PAM viscosity were identified and evaluated by the analysis of produced water quality used by the operation of preparation in Daqing oilfield. Effects of the specific ions on PAM viscosity were investigated in the lab test for understanding and controlling the viscosity. The results show that the dominant specific ions were found out to consist of the divalent cation (Ca²⁺ and Mg²⁺), trivalent cation (Al³⁺), divalent ferrous ion (Fe²⁺) and divalent sulfide ion (S^2-) by means of the data and related chemical theory. Much notable viscosity degradation of PAM solutions was observed in the degree-viscosity curves as the role of most of the specific ion factors. Totally, the retention rate of the viscosity was obviously lowered with the extension of the specific ion by degrees. By the results, the mechanism of the viscosity degradation was briefly proposed and discussed. These data can be provided and suitably specified for the benefit of polymer flooding production.

Abstract: Nowadays the immature of the precise synchronizer gear ring processing method have greatly impeded the development of the vehicle business in China. The extrusion process is a very important procedure in making precise synchronizer gear ring, but there is not any introductive and effective research yet to the issue of the optimal processing parameter in precise synchronizer gear ring procession. This research provides several processing parameters in precise synchronizer gear ring procession by means of simulating the processing in DEFORM-2D software and trying it in reality. The result shows that the whole three processing procedures have influence in the result of the gear ring. The second procedure is the most influential, followed by the fist procedure. Adjustment can be effectively conducted on the product of the first procedure by changing the fillet radius of the top die and the bottom die, R1, R2; adjustment can be effectively conducted on the product of the second procedure by changing the fillet radius of the top die and the bottom die and the angle of the upper inclination of the top die,α2. The result of this paper gives an instruction in precise synchronizer gear ring procession.

Abstract: The forging method with horizontal V – shaped anvil is introduced to control fibrous tissue flow direction through changing shape of anvil, its working face is composed of four projecting cone, it can realize no transverse tensile stress forging. For this, in the paper qualitative physical simulation was carried out. The results show that there was no crack between the hole and the pin in deformation zone of rectangular billet by horizontal V – shaped anvil forging method, therefore, the authors think that there no transverse tensile stress in deformation zone of billet in the forging process of horizontal V – shaped anvil.

Abstract: This paper presents a methodology to design optimal forming process parameters of the sleeper fixed reinforcing plate based on the use of computer aided engineering (CAE) technology. The methodology uses Unigraphics software to establish the numerical model and DYNAFORM software to simulate its sheet forming process to determine the feasible process parameters affecting its manufacturability, including whether the mould requires the binder, binder force, friction coefficient, and die fillet radius. The forming limit diagram and the thickness distribution diagram are selected to appraise and analyze the forming results. The orthogonal experiment method is adopted to simulate the design parameters to find out the optimum values for mould design.

Abstract: Because of the excellent specialties of intensity, rigidity, heat-durability, corrosion proof and wide uses in many fields, Al2O3 has a promising future. Supercritical hydrolysis is a new method to produce Al2O3 micro-particles whose average diameter is 537nm. The resulting samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Particle-size Analyzer. Its product is the high purity α-Al2O3 which is characterized by the features of the small particle size, the well developed dispersion, and the fine concentricity. The influences of process parameters, including pressure, temperature，total flux and ratio of branch flux, on particle size were investigated at the same time. The results indicated that the particle size has a significant increasing trend with an increase in the pressure and temperature; however, it decreased with an increase in the total flux, while it decreased slightly with an increase in the ratio of branch flux.

Abstract: Metal workpiece was processed by nanosecond pulsed laser electrochemical micro-etching with masks patterns in the shape of letter "E". In the experimental system established, the effect of different laser energy on processing quality was studied in air. In the different concentrations of the electrolyte, through optimized composite machining parameters, machining results of different laser energy with the masks were analyzed and compared in Aluminum alloy and Stainless steel. There was a large of difference in machining morphology by laser electrochemical micromachining with masks in two different metal materials. The results show that laser electrochemical micro-etching with masks has high efficiency and the prospects for the large-scale production, but the etching precision should be also further improved. Moreover, the nanosecond pulsed laser thermal-stress etching, electrochemical etching and the two combined coupling etching are the main factors to achieve the metal removal.

Abstract: This article presents the results of experiments that concerned on the surface roughness quality by drilling of a new Extra Low Carbon (ELC) austenitic stainless steel X01Cr14Ni9TiN. This article presents conclusions of machinability tests on new austenitic stainless steels X01Cr14Ni9TiN. The results of cutting zone evaluation under cutting conditions (cutting speed in interval vc=40-60 m/min, depth of cut ap=2.5 mm and feed f=0.01-0.12 mm per rev.).