Journal of Modern Processes in Manufacturing and Production
Year:2010 | Volume:1 | Issue:3|Papers Count:9

The purpose of this paper is to investigate the cutting forces in ultrasonic assisted milling (UAM) process of AISI 1020 steel. Vibrations are imposed to the workpiece by a special fixture we developed. With different values of depth of cut, the cutting forces in both conventional milling (CM) and UAM are measured. The obtained cutting forces in UAM are less than the ones in CM. The effect of ultrasonic vibration on the cutting forces decreases in large values of cutting depth in comparison with its corresponding low values. Experimental data show that UAM decreases the cutting forces in comparison with CM by 8% in average.

This article investigates the kinematic relationships in a harmonic drive gear box with a fixed circular spline. According to the results, the ratio of vertical to horizontal deflection of the flexspline is constant for all values of the applied load and it only depends on geometric dimension of the flexspline. The difference in gear teeth of the flexspline and that of circular spline can only take values of 2. According to the results, flexspline deflection reveals similar trends with that of a cylindrical shell. This manifests itself in terms of a correlation factor Cf, through which one can find flexspline deflection ratio using cylindrical shell results. This factor can play an important role in design of flexspline. Using the proposed design curves, one can calculate the required force for a full engagement of gear teeth.

Gas tungsten arc welding (GTAW), is one of the important methods used in industry and it is an arc welding process that uses a no consumable tungsten electrode to produce the weld. GTAW is most commonly used to weld thin sections of stainless steel and non-ferrous metals such as aluminum, magnesium, and copper alloys. In this research the authors have designed and manufactured an automatic welding arm in which its feed is controlled by a microcontroller. In different conditions like feed, ampere and pre-heat temperature practical tests have done and tensile strength of the welded parts has measured. Then by using this data an artificial neural network designed and tested. The inputs of the network are adjustable parameters of the welding process and the output is the tensile strength. The results show that by using neural networks we can determine the tensile strength precisely before the process.

In this study optimization of Taguchi experimental design objective function was carried out to find out the optimum conditions in water assisted injection molding process of ABS and PP. To produce the specimens, a branched pipe mold with an overflow cavity and water injection nozzle was designed and manufactured. Considering the different objective functions in this process, optimization of Overall Evaluation Criteria (OEC) method was used. The bigger-the better quality characteristics for objective function of OEC was applied. In present research water penetration and shrinkage difference of specimens was choose as objective function and holding time, mold temperature and delay time was considered as control variables. A Taguchi M9 orthogonal standard array was used for experimental design and the analysis of variance (ANOVA) method was considered for statistical analysis. The OEC results indicated that in ABS, delay time has the most effect on specimens’ quality characteristics and mold temperature and delay time affected the quality characteristics respectively. Results also showed that in PP, the holding time was the most affective parameter and delay time and mold temperature has effect on the quality characteristics respectively.

In this article in order to control wear properties of 1.7765 steel with many application in gas corrosive enviroment with high pressure and temperature, the effect of hard chrome coating, gas nitriding coating and nitriding of hard chrome coating is investigated. All of specimens, in every coating method  is inspected with optic microscop, micro hardness testing, XRD testing, pin on disk and oxidizing testing. Results of this investigations show that structur of chrome-nitrided surface mainly has CrN in surface with chrome layer that increase depth and amount of hardness, wear resistance and oxidizing resistance. Also there is not any difference in friction factor of chrome-nitrided sample and raw sample.

Creep feed grinding is widely used in manufacturing supperalloy materials. These materials are usually used in aircrafts, gas turbines, rocket engines, petrochemical equipments and other high temperature applications. The main objectives of this research deal with the influences of major process parameters and their interactions of creep feed grinding process such as wheel speed, workpiece speed, grinding depth and dresser speed on the lean of Ruston TA1750 Gas Turbine blade by design of experiments using design of experiments (DOE). After conducting the experiments, results are analyzed by variance analysis and predicted mathematic model of lean of turbine blade are obtained and by using these models and amount of desirable lean of blade, input parameters for optimum production are achieved. It is found that slower wheel speed with higher workpiece speed, smaller grinding depth and slower dresser speed, have advantages for obtaining smaller lean of blade within tolerance.

In recent years, in order to reducing die design and manufacturing costs, Multi point forming technique has gained an increasing interest because of its high flexibility. In this process, the conventional fixed shape solid die sets are replaced with a pair of opposite matrices of controllable elements. In this paper, the fundamental principles of multi-point forming was described and the possibility of forming the one sheet metal part by this technique was investigated experimentally and analyzed using finite element simulation. Wrinkles and dimples are the most typical defects in multi-point forming of sheet metal. By the proper selection of process parameters the sound cup with good surface quality and uniform thickness distribution can be formed. The results obtained demonstrated that multi-point forming technology can be used as an effective and economic tool to the forming of single parts with different shapes and is cost-effective.

Optimization of process parameter is one of the ideal goals in laser sintering. The results of this process were measured as out-put parameters like: density, micro hardening, macro hardening, tension, roughness, stiffness, balling. In this paper, the influence of input parameter such as laser power, scan speed, material powder and etc are surveyed on output parameter like balling affection and the thickness of a layer. Iron and copper powder were used in this experiment in order to produce a full density single layer on 5 mm depth bed powder. One of the efficient factors on this process is overlapping which has a reverse impact on the high and low pulse power. Finally a coupon was produced with the best setting.

Nowadays, tube bonding in vehicles structure is noticeably considered by many researches. In this paper, local tube compression process by a rubber ring has been studied. Firstly, simulation of the process was performed by FEM. Then, experimental test has been carried out to validate the numerical results. Numerical and experimental results were compared showing a good agreement. In the second part of this study, tube assembling of a two tubes was examined by a rubber ring. The simulation results have presented including stress distribution of both tubes. Finally, this method was compared with other tube assembling methods by observation of tube profile deformation.