Papers by Keyword: Dimensional Deviation

Abstract: Over the years, with the increasing development of engineering materials, the emergence of new composites, fiber metal laminated, biomaterials, metal alloys etc., and with demand for products less expensive, less polluting and more efficient, the manufacturing engineering also needs to develop to be able to process these new materials. Materials and tool geometries, intelligent mechanisms, modular machines, also follow this setting. To that end, this work comes to raise the main parameters that influence in the hole quality surface of finished product. Were used two polymeric materials, ultra high molecular weight polyethylene (UHMW-PE) and polytetrafluoroethylene (PTFE), two feed rates, three rotations and three tool geometries, allowing to identify which of these parameters have greater influence on the thrust force and the characteristics of the finished product and dimensional deviation.

Abstract: Wire Electric Discharge machine is non-conventional thermo-electric spark erosion machining process to cut conductive metal and alloys. The main mechanism of machining is spark erosion between the tool and work-piece. High carbon high chromium tool steel (D-2) is a hard alloy with high hardness and wear resisting property. The purpose of this study is to investigate the effect of process parameters on the machining of D-2 tool steel. D-2 tool steel used in tool and die industries. Response Surface Methodology (RSM) is used to formulate a mathematical model which correlates the independent process parameters with the desired dimensional deviation. The central composite rotatable design has been used to conduct the experiments. Genetic algorithm is used to predict the best individual parameters along with the predicted fitness values.

Abstract: Performance of machining processes is assessed by dimensional and geometrical accuracy which is mentioned in this paper as dimensional deviation. A part quality does not depend solely on the depth of cut, feed rate and cutting speed. Other variable such as excessive machine tool vibration due to insufficient dynamic rigidity can be deleterious to the desired results. The focus of the present study is to find a correlation between dimensional deviation against cutting parameters and machine tool vibration in dry turning. Hence cutting parameters and vibration-based regression model can be established for predicting the part dimensional deviation. Experiments are conducted using a Computerized Numerical Control (CNC) lathe with carbide insert cutting tool. Vibration data are collected through a data acquisition system, then tested and analyzed through statistical analysis. The analysis revealed that machine tool vibration has significant effect on dimensional deviation where statistical analysis of individual regression coefficients showed p<0.05. The developed regression model has been validated through experimental tests and found to be reliable to predict dimensional deviation.

Abstract: In this work, in-mold rheology curves were generated by injection molding machine and the effects of feedstock and mold dimension on in-mold rheology curve were studied. The rheology within mold in µMIM process depends on the shape and/or size of cavity and process conditions rather than intrinsic viscosity of feedstock. The optimum injection speed was determined in region of Newtonian flow of in-mold rheology curve. The dimensional deviation was below about 5 µm in the micro part injected with the optimum speed.

Abstract: The present study show that metal cutting fluids changes the machinability because of their lubrication and cooling in turning 1Cr18Ni9Ti steel under minimum quantity lubrication (MQL) Machining. The experiments compares the mechanical performance of MQL to completely dry lubrication for the turning of 1Cr18Ni9Ti steel based on experimental measurement of cutting temperature, cutting forces, surface roughness, and dimensional deviation. Results indicated that the use of near dry lubrication leads to lower cutting temperature and cutting force, favorable chip-tool interaction, reduced tool wears, surface roughness, and dimensional deviation.

Abstract: The aim of this study is to find the influence of cutting parameters and tools on surface roughness and dimensional deviation for better production quality in machining 0Cr18Ni12Mo2Cu2 steel. The most important parameters like cutting velocities, depth of cut and feed rate are considered. The experiments designed four types of boring tool rake angle and two types of coolant, and measured surface roughness and radial runout of workpiece with three acclivitous holes. The results showed that the surface integrity of workpiece obtained by 0.16 mm/rev feed rate with rake angle of tool 25o were superior to that obtained by the previous boring processes. Radial runout precision was highest when feed rate and rake angle were 0.13 mm/rev and 23o, respectively. According to experimental results, the rake angle and structure of boring tool were improved.

Abstract: Experiments under a cold rotary swaging process have been conducted to investigate the dimensional characteristics of the swaged tube and solid bar for obtaining proper product of desirable quality. Dimensional characteristics are expressed in terms of dimensional deviation and surface roughness of swaged product through the rotary swaging process. The process variables such as forming speed and percent reduction of outer diameter of the product are considered and selected because of playing a key role in the rotary swaging process. Furthermore the developed rotary swaging machine with four-split dies, named as KRSM25, is used in the swaged experiment. Based on the experimental results, it is observed that the process variables affect the quality of swaged product such as dimensional precision, surface roughness of the product. Defect could be found to occur at a value of more than 2.0 mm/rev in forming speed. The dimensional precision of swaged product depends on the percentage reduction of outer diameter and forming speed. The work presented in this paper might be used for available information in the design of the optimum rotary swaging process.