THE MEASUREMENT AND THE INTERPRETATION OF THE FORCE PARAMETERS DURING ECAP PROCESS
Abstract
Production of ultrafine-grained metal materials represents modern and high perspective area of metallurgy. Currently, there are several methods for producing these materials. Severe plastic deformation (SPD) is one of the ways to prepare them. Equal-channel angular pressing (ECAP) is one of the most efficient techniques of SPD for production of bulk ultrafine-grained metals. In the SPD process is important of measurement deformation forces. The strain gauges sensors measure the strain forces with the necessary accuracy. About progressing action of plastic deformation can be assumed from the measured deformation forces. These forces include friction in contact points of metal with matrix. The article describes experimental methodic measuring deformation force with strain gages by laboratorial equipment NI cDAQ and commercial software LabView. Deformations curves of the ECAP process are described to alloy EN AW 6060 and of OFHC (Oxygen Free High Conductivity) Cu after zonal purification. Maximum values of deformation forces (Fmax) in the first ECAP passes show scatter 23 kN, which represents the total measurement range of 23%. In following ECAP passes the scatter was decreasing. Fourth pass of the sample OFHP Cu reported scatter values Fmax 4,7%. Scatter Fmax of the sample EN AW 6060 in the third ECAP passes was reduced to 4 %. Samples of alloy EN AW 6060 during extrusion decrease of deformation forces in following ECAP passes. The samples of the OFHC Cu showed an increase of deformation forces.
Keywords: ECAP|severe plastic deformation|force|transducer|OFHC Cu|EN AW 6060|
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