M.A. El Baradie

COMPUTER-AIDED ANALYSIS OF A SURFACE-ROUGHNESS MODEL FOR END MILLING

Abstract The factors which affect the surface finish produced in the end milling process are generally the cutting speed, the feed, the depth of cut, etc. This paper describes a study of the development of a surface-roughness model for the end milling of 190 BHN steel. The model for the mathematical prediction of the surface roughness has been developed in terms of cutting speed, feed and axial depth of cut. The effect of these cutting parameters on the surface roughness has been investigated using response surface methodology. Response surface contours were constructed by computer and used for determining the optimum cutting conditions for a required surface roughness.

Cutting fluids: Part I. Characterisation

Abstract The selection and application of cutting fluids in industry have not always been accomplished in an optimal manner. When properly applied, cutting fluids can increase productivity and reduce costs by making possible the use of higher cutting speeds, higher feed rates and greater depths of cut. Effective application of cutting fluids can also increase tool life, decrease surface roughness, increase dimensional accuracy and decrease the amount of power consumed. Part I of this paper presents an overview of the cutting fluids, their classification and composition. While Part II addresses the issues of clean machining technology, mainly recycling and disposal of cutting fluids.

Optimization of surface finish in end milling Inconel 718

Abstract This paper presents an approach to optimize the surface finish in end milling Inconel 718 using uncoated carbide inserts under dry conditions. In view of this, the mathematical models for surface roughness have been developed in terms of speed and feed by response surface methodology. Response surface contours were constructed in speed feed planes by computer. From these contours it was possible to select a combination of cutting speed and feed that reduces machining time without increasing the surface roughness. These were obtained by superimposing the constant lines of metal removal rates on the surface roughness contours.

Prediction of tool life in end milling by response surface methodology

Abstract This paper presents a study of the development of mathematical models for tool life in end milling steel (190 BHN) using high-speed steel slot drills under dry conditions. The predictive models for tool life have been developed in terms of primary machining variables such as cutting speed, feed and axial depth of cut by response surface methodology. A first-order equation covering a narrow range of the variables and a second-order equation covering a wide range of the variables are presented. Response surface contours were constructed in speed-feed planes and used for determining the optimum cutting conditions for a required to life. The adequacy of the predictive models was tested by analysis of variance and found to be adequate.

Plastics and their machining: A review

Abstract Many different families of plastics are used in industry. The demand for the machining of plastics has recently increased. In most cases, traditional metal machining techniques and tools are being used in the machining of plastics. The present paper reviews the conventional mechanical machining of plastics. The cutting phenomena as indicated by the types of chips formed under various cutting conditions, and the cutting forces for the single-edge cutting of two broad types of plastics are discussed. When drilling plastics, the type of chip produced, the torque, and the thrust are considered. A general idea about the milling of plastics is shown. The possibility of grinding thermosets and thermoplastics using an open grinding wheel is discussed with reference to bond type, grit type, grit size and porosity.

Cutting fluids: Part II. Recycling and clean machining

Abstract It is widely recognised by machine tool users that the effect of the cutting fluids on the environment, particularly in regard to their degradation and ultimate disposal is a major problem. Also because the machine tool operator is always in the general area of a cutting fluid, the effects of contact with the fluid is of primary concern. In addition to fumes, smoke, bacteria and odours, the fluid can also cause severe reactions on the skin and various parts of the operators body. The classification and composition of cutting fluids have been discussed in part I [1]. While this paper (Part II) addresses the issues of the clean machining technology mainly recycling and disposal of cutting fluids.

Fuzzy logic based intelligent selection of machining parameters

Abstract Fuzzy logic principles have been applied for selecting cutting conditions in machining operations. The materials data used for theoretical calculations were for medium carbon leaded steel (BHN 125–425) and Freemachining carbon wrought steel (BHN 225–425). Three different depths of cut (1mm, 4mm and 8mm) and four types of tools were used for these theoretical study, I) High Speed Steel Tool, ii) Carbide Tool-Coated, iii) Carbide Tool-Uncoated Brazed and iv) Carbide Tool-Uncoated indexable.

Metal-matrix composites: Materials aspects. Part II

Abstract In Part I (Metal matrix composites: Manufacturing aspects) six different fabrication routes were discussed for manufacturing MMC materials, these being: PM, diffusion bonding, liquid-metal infiltration, squeeze casting, spray codeposition and compocasting. Amongst them, the squeeze-casting technique is used widely for the continuous production of MMC materials. MMC materials are produced with a mixture of matrix and reinforcement materials. In this paper an analysis of the matrix and the reinforcement is given and a potential solution is enumerated for selecting the proper matrix and reinforcement materials to form the MMC.

Metal-matrix composites: Manufacturing aspects. Part I

Abstract In recent years the potential of metal-matrix composite (MMC) materials for significant improvement in performance over conventional alloys has been recognised widely. However, their manufacturing costs are still relatively high. This paper (Part I) surveys and outlines the different manufacturing routes employed currently in the production of MMC. An economic assessment of each route is discussed together with the selection of the most economic route for a particular application. Part II surveys and outlines the properties of matrix/reinforcement materials and discusses the procedure of selecting the proper matrix/reinforcement materials combination.

A fuzzy logic model for machining data selection

This paper describes the development stages of a fuzzy logic model for metal cutting. The model is based on the assumption that the relationship between the hardness of a given material and the recommended cutting speed is an imprecise relationship, and can be described and evaluated by the theory of fuzzy sets. The model has been applied to data extracted from the Machining Data Handbook [Metcut Research Associates, 3rd edn, Vols 1 and 2 (1980)], and a very good correlation was obtained between the handbook data and that predicted using the fuzzy logic model. The objective of the model is to facilitate the computerization process of the vast machining information contained in machining data handbooks. Also, the proposed model suggests the possibility of developing an expert system for machining data selection based on fuzzy logic.