The surface roughness obtained by the cutting processes has always been a subject of great interest when it is intended to improve the quality of the final product requested by the customer. The ...objective of this scientific paper involves a comparative study on the tracking of the surface roughness measured both longitudinally and transversely in the direction of the cutting feed movement, following the end-milling process of an aluminum alloy used in the aerospace industry worldwide. Practical experiments have conducted in a prestigious company in the aerospace industry of Romania. Regarding the cutting regime, in terms of milling, a cutting speed was adopted to maintain its constant value at 570 m/min, and the cutting depth and feed per tooth are within the range recommended by the cutting tool manufacturer in aluminum machining. The measuring and control devices used to obtain the experimental data were chosen after careful analysis, such as the surface tester and the electronic microscope. With the help of the obtained data, it was possible to interpret the surface roughness results measured longitudinally in the direction of the feed motion, compared to the roughness measured transversally in the same direction of the cutting tool. Different variations of the surface roughness have highlighted with the help of profiles and microscopic analyses of the machined surfaces. This study is in the category of scientific papers with an extremely high level of applied scientific research using experimental statistical modeling of active type.
In the aerospace industry, the milling of aluminum alloy parts is a machining process with the primary purpose of removing high volumes of material. Aluminum alloys are materials that have relatively ...good machinability, which helps the process because many of the components of the aircraft are of high dimensions. These parts have many pockets more or less deep, and the removal by cutting off about 90% of the initial volume of the workpiece is a matter of consideration. The manufacturing process is protracted and involves long semi-finishing and finishing operations, so it is recommended that any researcher who begins and finishes an experimental study should do it base on a specific experimental plan. Mathematical statistics techniques and methods are used, but also optimization methods that lead to a rational choice of process parameters, process input data and objective functions that need to be improved. This scientific paper presents applied research based on an extremely pertinent active experiment that has led to some practical solutions applied in the aerospace industry worldwide. The dedicated objective function on which the study conducted in this case was the mean arithmetic deviation of the surface profile. The independent variables were chosen by the concrete application of a dispersion analysis applied to the milling process, namely the cutting speed, the cutting depth and the feed per tooth. Interpretation of the results was performed by a graphical evaluation of the normality of the data distribution, by presenting the histogram responses as well as by the dispersion diagrams. It was used for a better correlation a 3D graphical analysis that followed the Ra variation of the mean arithmetic deviation of the machined surface profile under the influence of the cutting parameters and the independent variables respectively. The obtained conclusions led to the validation of the experimental model and the application of the research presented within an aerospace industry organization with important global valences.
The surface quality study of the cutting processes is a very current and complex subject, which approached in variously specialized researches. This paper is a continuation of our previous research. ...The primary objective of this paper is to track the evolution of the surface roughness measured longitudinally on the feed motion direction in the end-milling process of an aluminum alloy used in the aerospace industry. The active experiment is the research method used to achieve the proposed objective. The cutting regime adapted to carrying out the necessary experiments supposes a constant cutting speed, while the cutting depth varies with different values. Obtaining the experimental data did possibly using the roughness tester as a measuring device. The obtained measurements were used to determine the surface quality evolution in the various situations of the cutting regimes resulting from the combination of the process parameters considered in the analysis. The experimental study is very complex and carried in an industrial organization that focuses on the aerospace industry. Through this original research that was carried out in the smallest details, a series of comparative graphs of the surface roughness evolution performed under the cutting depth variation, which led to a package of conclusions to have taken into consideration.
Metastatic tumors account for 5-10% of all ovarian malignancies. They are usually bilateral tumors with a multinodular surface and extensive extra ovarian spread. Lung cancer is a rare source (0.3% ...of metastatic ovarian tumors). Among synchronous primary cancers, ovarian cancer is most frequently associated with endometrial cancer. The differential diagnosis between a primary ovarian carcinoma, synchronous primary cancers, and metastatic ovarian carcinoma is very important, as the treatment and prognosis are markedly different. We report the case of a 25-year-old woman who had been diagnosed and treated for stage IIIB small cell lung carcinoma (SCLC). Imaging undertaken for abdominal pain revealed a unilateral 8.5 cm ovarian tumor for which adnexectomy was performed. Histology and immunohistochemistry led to the diagnosis of ovarian metastasis from SCLC, a high-grade neuroendocrine lung tumor. This patient's particular features, all infrequent in a metastatic tumor, are the lesion's unilaterality (atypical for ovarian metastases in other cancers, but often observed in SCLC), the smooth ovarian surface with intact capsule, and the absence of intra-abdominal dissemination. The patient developed liver and vertebral metastases. This report focuses on the differential diagnosis between primary and metastatic ovarian neoplasms. We performed an extensive search of the literature on SCLC and ovarian metastases. Immunohistochemistry is essential for diagnosis when imaging and the pathological evaluation of the ovarian tumor cannot make the differential diagnosis.
As a part of the cutting process, a researched aspect continuously is surface quality. Based on and using the results of previous research, the present scientific paper addresses the problem of the ...machined surfaces roughness. The cutting process approached in this study is the end-milling one, and the workpiece material used to carry out the study is the aluminum alloy used in the aerospace industry. The adopted cutting regime imply to keep the cutting speed at a constant value while the cutting parameters: cutting depth and feed per tooth vary with different values. The experimental research carried out by the authors in a prestigious industrial company is complicated and complies with the specific methodology. The conclusions stand based on the interpretation of the results obtained from the experiments which were carried out based on the active experimental type. The confirmation of the obtained results was performed using the profiles and images of the microscopic analysis of the machined surface.
In the metal cutting process, surface quality is intrinsically related to the cutting parameters and to the cutting tool geometry. At the same time, metal cutting processes are closely related to the ...machining costs. The purpose of this paper is to reduce manufacturing costs and processing time. A study was made, based on the mathematical modelling of the average of the absolute value deviation (Ra) resulting from the end milling process on 7136 aluminium alloy, depending on cutting process parameters. The novel element brought by this paper is the 7136 aluminium alloy type, chosen to conduct the experiments, which is a material developed and patented by Universal Alloy Corporation. This aluminium alloy is used in the aircraft industry to make parts from extruded profiles, and it has not been studied for the proposed research direction. Based on this research, a mathematical model of surface roughness Ra was established according to the cutting parameters studied in a set experimental field. A regression analysis was performed, which identified the quantitative relationships between cutting parameters and the surface roughness. Using the variance analysis ANOVA, the degree of confidence for the achieved results by the regression equation was determined, and the suitability of this equation at every point of the experimental field.
The resulting surface quality after the cutting process is one of the most important characteristics of product quality and also the most frequent customer requirement. Previous research was focused ...on the effect investigation of machining parameters: cutting speed 1 and feed per tooth 2 on surface roughness. This paper is in itself a continuation of a previous research 3, in which, with Taguchi's method it was determined the level of influence of the cutting parameters on surface roughness of 7136 aluminium alloy in end milling process. The purpose of this paper is to highlight the importance of Taguchi's method use to analyse the surface roughness of 7136 aluminium alloy in end milling process. To conduct the experiments, three cutting parameters were used: cutting speed, feed per tooth and cutting depth. To analyse the surface quality, the surface roughness Ra (the arithmetic average of the absolute values) was measured. It was determined the recommended configuration regarding the optimum values of each machining parameter and the interactions between them, in order to obtain the better cutting process performance and to reduce the surface roughness sensitivity to uncontrollable factors. Based on a full factorial experiment were confirmed the obtained results by applying the Taguchi's method. Final results are a starting point for further research.
The present paper intends to highlight the utility and importance of HMI in the control of the robotic arm, commanding a Siemens PLC. The touch screen HMI Weinteke MT3070a is the user interface in ...the process command of Siemens PLC, in which the distances and displacement speeds are introduced on the three axes. The interface includes monitoring robotic arm movement but also allows its command by incrementing step by step the motion over axis.
The present paper deals with a current and complex topic, namely - a technical problem solving regarding the modeling and then optimization of some technical parameters related to the natural gas ...extraction process. The study subject is to optimize the gas probe sputtering using experimental research methods and data processing by regular probe intervention with different sputtering agents. This procedure makes that the hydrostatic pressure to be reduced by the foam formation from the water deposit and the scrubbing agent which can be removed from the surface by the produced gas flow. The probe production data was analyzed and the so-called candidate for the research itself emerged. This is an extremely complex study and it was carried out on the field works, finding that due to the severe gas field depletion the wells flow decreases and the start of their loading with deposit water, was registered. It was required the regular wells foaming, to optimize the daily production flow and the disposal of the wellbore accumulated water. In order to analyze the process of natural gas production, the factorial experiment and other methods were used. The reason of this choice is that the method can offer very good research results with a small number of experimental data. Finally, through this study the extraction process problems were identified by analyzing and optimizing the technical parameters, which led to a quality improvement of the extraction process.
This paper presents a study on the modelling and optimization of certain variables by using the Taguchi Method with a view to modelling and optimizing the process of pressing tappets into anchors, ...process conducted in an organization that promotes knowledge-based management. The paper promotes practical concepts of the Taguchi Method and describes the way in which the objective functions are obtained and used during the modelling and optimization of the process of pressing tappets into the anchors.
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