Adaptive Control System for Optimizing the ECG Process under the Overcut Constraint
One of the main limitations 1n Peripheral Electro Chemical Grinding (ECG) is the overcut phenomenon. The dominant parameters which govern the dimensions of the geometrical overcut are the voltage and the feedrate. This paper deals with the development of an empirical model which describes the overcut as a function of the dominant parameters. Pased on this model an adpative control system was built and experiments in Profile Peripheral ECG were carried out. A comparison of the results obtained with and without the adaptive control system is presented as well as the relationship between the side and bottom overcuts. According to the above an adaptive strategy to control the geometrical overcut in Profile ECG is suggested.
An Experimental Investigation of the Electrolytic Grinding Process
Data are presented covering the effect of several variables on grinding rate for the electrolytic grinding process. The relative amount of material removal due to electrolysis and due to conventional grinding action was investigated. The Faraday current efficiency of the electrolytic part of the process was found to be near 100 per cent to the extremely high current density of 700 amps per sq in. This is thought to result from the scraping action of the wheel abrasive which prevents passivation of the work anode. Several phenomena of the process are explained on the basis of hydrogen gas pressure in the work-wheel interface. A formula is presented for calculating the hydrogen gas pressure. Equations are proposed for the basic chemical reactions of the process.
Microstructural interpretation of the stress-strain behaviour of the WCCo composite material
Abstract Of the two phases forming the WCCo structure the binder phase is strengthened in three ways: solution hardening, tri-axial stress state, and dislocation repulsion from the WC grains, Different types of deformation of the carbide network are discussed. Their contribution to the non-elastic behaviour of the composite is found to be negligeble, and so attention is dicreted to the deformation properties of a number of carbide-binder-carbide configurations. Two such configurations are analysed in detail, and one of them, which corresponds to a mechanical model earlier proposed by the author, is found to have non-elastic properties very similar to those observed for WC-Co alloys.