Comparison Analysis Between Simulation and Experiment of Cutting Force and Cutting Stress as Well as Chip Morphology During the Macro and Nano Cutting of Single Crystal Copper

In this paper, the simulation and experiment comparison of cutting force, cutting stress and chip morphology during the macro and nano cutting of single crystal copper are carried out. Firstly, a finite element method based on Johnson-Cook metal strength and failure model were used to establish a macro cutting model, and the cutting force, cutting stress, cutting displacement and chip morphology were obtained. Then a molecular dynamics simulation was used to establish a nano cutting model, and the cutting force, von mises stress and chip morphology were obtained. Afterwards, a comparative analysis of the two was carried out. Finally, the external turning experiment was used to verify the simulation results of the macro cutting model. The results show that: 1. The change trend of the cutting force in x and y directions are different,but the corresponding ratios of cutting forces in x and y directions in macro and nano cutting process are very close, and the corresponding ratios of the average macro and nano cutting forces in x and y directions are also very close. 2. The cutting stress in nano cutting process was about 100 times of macro cutting stress. 3. The chip length in macro cutting process is larger than the chip length in nano cutting process, and the shape is more regular. 4. The experimental cutting force change trend is very similar to the simulation cutting force change trend, but there exits difference in the value between the experiment cutting forces and simulated cutting forces.

Microstructural Characterization of a Single Crystal Copper Rod Using Monochromatic Neutron Radiography Scan and Tomography: A Test Experiment

This paper reports the analysis of a single crystal copper rod aiming to characterize the microstructural features related to the homogeneity of the single crystal growth and the presence, shape and extension of spatially distributed misaligned grains or areas. The analytical method used for such analysis is wavelength scan neutron radiography and monochromatic neutron tomography. Such methods allow determination of the extent of differently oriented single crystal areas, identifying the most part of the rod volume as a single domain. It was also possible to characterize the spatial distribution and the degree of alignment of local point-like or extended defects.