G.K. Lal

An experimental study of abrasive jet machining

Abstract The paper presents the experimental results obtained on a specially designed abrasive jet machining set-up. The effects of various input parameters such as stand-off distance, mixture ratio, carrier fluid pressure, grain size, etc. on the material removal rate as well as penetration rate have been studied. The results have been discussed on the basis of existing erosion models.

Profit rate maximization in multipass turning with constraints: a geometric programming approach

Geometric programming (GP) has been successfully used for the determination of cutting parameters considering minimum production cost or maximum production rate as objective functions. However, GP was found not to be useful for another important criterion of optimization, namely maximum profit rate, due to its signomial nature. In this paper it has been shown that, through modification of the constraint set, the problem of profit rate maximization can be converted to posynomial form, and thus can be solved by GP combined with linear programming (G P-LP). The problems of single and multipass turning are formulated and solved for profit rate maximization using the GP-LP approach. The resulting cutting conditions have been compared with the conditions obtained for minimum production cost and maximum production rate.

Effect of dressing on grinding wheel performance

Abstract The grinding wheel performance is significantly affected by the way the wheel is dressed. The two important variables in single point diamond dressing are the dressing depth of cut and the cross-feed rate. The effect of these two parameters have been studied in terms of grinding ratio and wheel life and the optimum dressing conditions have been evaluated from economic analysis.

Surface generated in fine grinding. Part 1 Probabilistic model

Abstract In this paper, a theoretical model is proposed to describe the probability density functions of the random positions of grains on the wheel surface based on the interference of grooves by different grains. It also describes an algorithm for the theoretical simulation of both transverse and longitudinal surface profiles generated during fine surface grinding.

A new technique for evaluating wheel loading

Abstract The X-ray fluorescence technique using high energy Am 241 as X-ray source has been applied for the study of the grinding wheel loading. Experiments with lead and mild-steel workpieces indicate the sensitivity and feasibility of this technique. The quantitative values of loaded material have been evaluated through calibration with standard samples. Results obtained using this and a conventional technique show close agreement.

An experimetnal study of oblique cutting with single-ended tools

Abstract Experimental results obtained during oblique cutting of mild steel and brass with single edge tools are presented. Measurements of forces, chip flow angle, cutting ratio, shear angle etc. have been carried out under a wide range of cutting conditions and the effects of various parameters have been examined. Experimental values have also been compared with various proposed flow rules with regards to their suitability.

A simple model for evaluating surface roughness in fine grinding

Abstract In this paper a simple model for evaluating surface roughness in fine grinding has been proposed. The concept of radial distribution parameter and effective profile depth associated with the stochastic model has been used to obtain the distribution of grains on the wheel surface. The approximate analysis yields values which agree reasonably well with the experimental results.

Wheel wear in dry surface grinding

Abstract Wear phenomena accompanying dry surface grinding of mild steel under plunge cut conditions were investigated from the force pattern, grinding ratio and wear particle size removed from the wheel. Wheel wear estimates were obtained from the amount of abrasive grains collected during grinding. The method proposed for evaluating the performance of grinding wheels can be adopted for the selection of grinding wheels.

Surface generated in fine grinding. Part 2. Radial distribution parameter and simulated surface profile

Abstract This paper provides the statistical analysis to obtain the functional dependence of the radial distribution parameter on grinding conditions by comparing the power spectra of the simulated and experimental profiles. A numerical technique to evaluate the power spectral density and generation of surface profile with all random possibilities of interaction of grooves is also presented. It is found that the radial distribution parameter is linearly related to table speed and depth of cut in fine grinding. Results indicate that the power spectra of simulated and experimental profiles are in close agreement.

On the dressability of abrasive grains

Abstract In this study the overcut fly milling technique has been used to evaluate the cutting performance of several grain types after diamond dressing. Results show that the cutting performance of the ductile grains deteriorates significantly after dressing while the effect is insignificant for friable grains.