**4. Results and discussion**

## **4.1 Validation of model**

For investigation of the validity of the mathematical model of MRR, the predicted results are compared with the experimental results from DiBitonto et al. [3] as shown in **Table 2**. It can be seen that the results predicted by the proposed model of MRR have a close agreement with the experimental results.

#### **4.2 Comparison of different models**

 To obtain the prediction accuracy and to explore the generalization capabilities of this model to the real state EDM process, a comparative analysis of different models (Our model, DiBitonto et al. [3], Joshi and Pande [9], Assarzadeh and Ghoreishi [11], Ming et al. [12]) has been made here. The machining conditions used for development of our model were exactly the same as adopted by the reported models. The results of the experiments, predicted by other models as well as our model, are shown in **Table 2**. **Figure 1** shows the comparison of MRR predicted by different analytical and numerical models as well as the experimental data. It is observed that our model exhibits the same tendency of variation as that offered by either experiments or other models. It can also be seen that the values of MRR predicted by our model are much closer to the experimental results when compared to those by reported models. The fraction


#### **Table 2.**

*Comparison of the experimental and predicted results.* 

*Modeling of Material Removal Rate in Electrical Discharge Machining by a Novel Approach… DOI: http://dx.doi.org/10.5772/intechopen.81083* 

**Figure 1.**  *Comparison of the theoretical and experimental results on MRR.* 

of energy transfer is a critical parameter to obtain material removal rate and the models of DiBitonto, Joshi and Assarzadeh have assumed constant fraction of energy transfer to workpiece, which is likely to depend on the discharge current and the pulse duration. Ming et al. [12] used a fraction of energy transfer equation based on discharge current and pulse on time but it was derived considering proportionality coefficient due to different work material. All these numerical and analytical models deviate remarkably from the experimental results exhibited by DiBitonto et al. [3]. This reveals that the assumption of a constant fraction of energy transfer to the workpiece is most likely to be incorrect. In our model, the fraction of energy transfer equation based on discharge current and pulse on time is derived from experimental data incorporating real state conditions. Thus, it could be concluded that our model is more suitable and accurate in predicting the MRR when compared to the reported models.

#### **5. Conclusion**

Modeling is important for any machining process as it helps in the prediction of performance measures. Researchers have used various techniques such as mathematical modeling, dimensional analysis, numerical modeling, regression modeling, etc. for modeling the EDM process. In this paper, a novel technique for modeling of the MRR is introduced based on the material removal mechanism and regression method. For the development of the MRR model, experimental data were used from literature (DiBitonto et al. [3]). To investigate the prediction accuracy, values of MRR obtained from our model were compared with the results of earlier analytical and numerical models and the published experimental data. It was found that the MRRs predicted by our model had much closer proximity to experimental results than those reported by other models. This model can further be used to conduct comprehensive studies on the EDM process to acquire optimal performance.

*Proceedings of the 4th International Conference on Innovations in Automation...* 

## **Author details**

C.R. Sanghani1 \*, G.D. Acharya<sup>2</sup> and K.D. Kothari3

1 School of Engineering, R. K. University, Rajkot, Gujarat, India

2 Atmiya Institute of Technology and Science, Rajkot, Gujarat, India

3 Mechanical Engineering Department, School of Engineering, R. K. University, Rajkot, Gujarat, India

\*Address all correspondence to: scr1385@yahoo.com

© 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

*Modeling of Material Removal Rate in Electrical Discharge Machining by a Novel Approach… DOI: http://dx.doi.org/10.5772/intechopen.81083* 

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