Applied Mechanics and Materials Vols. 799-800

Abstract: It was researched the interaction of composite brazing alloy Sn-Cu-Co-W with surface of diamond during formation of a diamond-bearing layer on abrasive tool. It was determined the influence of the composite brazing alloy components on wetting of diamond grains and their subsequent retention in metal matrix. The prototypes of stone-machining routers were manufactured with use of the designed composite brazing alloy. Thickness of obtained diamond containing coating is even over the entire surface is 2 mm. Due to the high viscosity of the composite brazing alloy it is well retained on the contoured surface of the substrate including the vertical sections.

Abstract: This study has developed a model in order to show the relationship between deflection of the low-rigidity processing system such like thin-walled component and the flexible milling force. The new model takes the deflection of cutter-workpiece system into account. The cutting force is analyzed simulatively by utilizing modified Newton–Raphson iterative algorithm. The simulative results show that the total normal deflection of workpiece–cutter system is the main factor affecting the change of cutting force.

Abstract: The process of circular saw blades sawing hedge branches belong to typical highly nonlinear penetration problems, so it is difficult to measure the actual cutting force, and it will have different characteristics with the variational saw feeding speed. The result of display dynamic analysis in the ANSYS/LS-DYNA module to circular saw blades sawing branches can be very close to the actual results. This paper make the numerical simulation for the regular pattern of cutting force with the variational saw feeding speed, analysis the force of circular with the saw feeding speed, and get some variation of circular saw blades sawing process by force, which laid foundation for the future study.

Abstract: This paper presents a novel approach for the optimization of machining parameters on turning of Mild Steel alloy with multiple responses based on orthogonal array with grey relational analysis. Experiments are conducted on mild steel alloy. Turning tests are carried out using coated carbide insert under dry cutting condition. In this work, turning parameters such as cutting speed, feed rate and depth of cut are optimized considering the multiple responses such as Energy Consumption (EC), and Material Removal Rate (MRR). A grey relational grade (GRG) of 0.746 is determined from the grey analysis for experimental run 27 meaning the control factors of this combination exhibit a stronger relationship with the response variables. Therefore, a spindle speed of 440 rpm, a feed rate of 0.24 mm/rev, and a depth of cut of 0.75 mm is the optimal parameter combination for the turning operation. The order of importance determined for the controllable factors to the Energy Consumption, in sequence, is the feed rate, spindle speed and depth of cut; while order to the Material Removal Rate, in sequence is depth of cut, feed rate and spindle speed. Optimum levels of parameters have been identified based on the values of grey relational grade and then finally, it was observed through ANOVA that the feed rate is the most influential and significant control factor among the three cutting parameters when turning mild steel in the conventional lathe tool, in order to minimize Energy Consumption and maximize Material Removal Rate.

Abstract: The problems of practical application of the combined electric diamond grinding (CEDG) are examined. Experiments were conducted on the grinding tool materials with metal-bonded diamond grinding wheels. In the presented part of the work, the roughness of the machined surface of specimens made of high-speed steel is investigated. It was established that the CEDG makes it possible to decrease the roughness of the machined surface to 30-40 % in comparison with other combined methods and 1.5-2 times in comparison with usual grinding. The application ensures the grinding by diamond wheels in the mode of self-sharpening and guarantees the continuity of its geometric form, which eliminates the defect layer on the machined surface and gives a longer period of wheel stability. The results obtained show that diamond wheels can be successfully used for grinding wide spectrum of tool materials.

Abstract: This paper investigates the effect of process parameters on surface roughness and chips formation in face turning of aluminium A2025 alloy international standard or A3035 alloy Korean standard using conventional lathe. The parameters namely the spindle speed, depth of cut and feed rate are varied to study their effect on surface roughness and chip characteristics. The experiments are conducted with all possible combination of factors in order to get the influence of every factor. The study reveals that the surface roughness is directly influenced by the spindle speed, depth of cut and feed rate. It is observed that the surface roughness increases with increased feed rate and depth of cut and is higher atlower speeds. The surface roughness analysis was done by atomic force microscope (AFM).The chips formed were continuous but varied in size and shape basing on the machining parameters. The depth of cut has no significant influence on the chips formation. The results shown here shows the ability of face turning method to test the surface roughness and chip formation on aluminium alloys. The face turning method used is simple and effective.

Abstract: The article presents experimental-based mathematical models for density, hardness and tensile strength of workpieces of iron-based powders, manufactured by molding with subsequent sintering. The experiment examines the powders of six brands, Russian and foreign. The diagrams show changes of the investigated values depending on brands of powders and pressures of molding compression. The impact of compaction schemes implementing significant shears between the compacted particles is estimated.

Abstract: This research proposed an in-process tool wear prediction during the ball-end milling process by utilizing the cutting force ratio. The dimensionless cutting force ratio is proposed to cut off the effects of the work material and the combination of cutting conditions. The in-process tool wear prediction model is developed by employing the exponential function, which consists of the spindle speed, the feed rate, the depth of cut, the tool diameter, and the cutting force ratio. The experimentally obtained results showed that the cutting force ratio can be utilized to predict the tool wear of ball-end milling tool. The new cutting tests have been employed to verify the model and the results run satisfaction. It has been proved that the in-process tool wear prediction model can be used to predict the tool wear regardless of the cutting conditions with the highly acceptable prediction accuracy.

Abstract: For hard disk drives (HDD), loose particles that are trapped between the head and disk during HDD operations can create damages to HDD. As a result, a nickel coating is used to minimize their loose particles. However, nickel is one of many carcinogenic metals known to be an environmental and occupational pollutant. Therefore, an electropolishing technique is proposed to replace a nickel coating process. To do experiments, a stainless steel actuator arm is set as an anode, a steel plate is set as a cathode, and a sulfuric acid is used as an electrolyte. With a design of experiment (DOE) technique, four parameters of the electropolishing technique which are an electrolyte concentration, an electrolyte temperature, a polishing time, and an electric intensity, are tested. The experiment result shows that the electrolyte concentration and electric intensity are not made any change for loose particles counts with liquid particle counter (LPC) testing whereas only two parameters which are the electrolyte temperature and polishing time play significant roles for LPC values. The lower LPC shows the smaller percentage of HDD failure. From these Box-Behnken DOE experiments, the optimal solution is 90 Celsius of the electrolyte temperature and 40 minutes of the polishing time. Although, the electrolyte concentration and electric intensity are not made any impact for LPC but they are set as a standard to be 0.2 mol/l and 0.25 A/cm² consequently. With these parameters, the predicted LPC is only 442,106 counts/part. This LPC is still in an accepted level standard that will not cause failure to HDD. This means that the electropolishing technique initially can be used to replace a nickel coating process without loose particles.

Abstract: The surface roughness is monitored using the cutting force and the cutting temperature in the ball-end milling process by utilizing the response surface analysis with the Box-Behnken design. The optimum cutting condition is obtained referring to the minimum surface roughness, which is the spindle speed, the feed rate, the depth of cut, and the tool diameter. The models of cutting force ratio and the cutting temperature are proposed and developed based on the experimental results. It is understood that the surface roughness is improved with an increase in spindle speed, feed rate and depth of cut. The cutting temperature decreases with an increase in tool diameter. The model verification has showed that the experimentally obtained surface roughness model is reliable and accurate to estimate the surface roughness.