Experimental analysis of subsurface integrity during fine turning of OFE copper for radiofrequency cavity manufacturing

Machining oxygen-free electronic (OFE) copper could be challenging but is not widely studied because few industrial or critical components requires to master the machined sub-surface characteristics. CERN radio frequency cavities are one of applications, especially turned surface functional final products. The niobium coating post process, which gives superconductive properties cavity, largely depends on present study relies an experimental approach cutting through thermal and mechanical probing high precision, pollution free, turning. Cutting forces load tool detailed for finish uncut chip thickness, defined at macroscale as limit between ploughing behavior, also a frontier microscale. Consequently, integrity evaluated by advance microstructural analysis (EBSD FIB), imposed thinness affected layer. Grain recrystallization appears in first 0.6 micrometers below deformed grains observed up 4 regime, while thickness layers three time larger case regime. Hence OFE turning characterized optimal conditions defined. research shows that simple tests can quickly narrow down condition, then confirmed metallurgical analysis, even edge pure copper, hence relevant other material.