(a1) and (b1), along the [100] cutting direction; (a2) and (b2), along the [101] cutting direction. In order to have a clear understanding of the mechanism of the damaged layer after nanocutting, the cutting along two directions should be given. The this website interaction force, especially the X-direction load (F x ) between the cutting tool and specimen, provides adequate pressure for nucleation and motion of dislocations which will lead to plastic deformation of

the material in the specimen. In addition, the local pressure should be large enough for dislocations to pass through the other defects in the specimen. After the nanocutting process and a long enough stage of relaxation, the copper atoms on the machining-induced surface reconstruction and finally some vacancy-related defects are selleck inhibitor located on the surface, which derive from the propagation of dislocations in material deformation. The larger F x results in a larger scale of glide directions in the specimen, which leads to much more serious plastic deformation underneath the tool. Figure 

10 shows the variation of cutting force along the X direction on the specimen in the two models, respectively. Firstly, the cutting forces increase with the cutting tool thrust into the specimen. The curve is not smooth, and the value of pressure varies significantly. Selleck BI 10773 Then, the cutting forces are fluctuating around a certain value. It is obvious that the cutting force (F x ) along the [ī00] direction is larger than that along the [ī01] direction. There are two reasons that may be responsible for this result. First, the process of dislocation nucleation under the cutting tool is continuous

due to the cutting tool moving forward with high velocity; second, the motivation across dislocations underneath the cutting L-NAME HCl tool causes a great change in both the atomic structure and cutting force. For the same cutting parameters and crystal orientation along the Y direction, during the cutting process, the values of F y are the same. More studies on how the dislocations influence the deformation along two cutting directions are stated in the following paragraph. Figure 10 Comparison of forces F x during the cutting processes along [ī00] and [ī01] crystal orientations, respectively. In order to measure the damage after nanocuttings along different crystal directions in quantity, the load-displacement (or indentation depth) curves of a complete nanoindentation from the MD simulation after nanocuttings are shown in Figure  11. It shows that at the maximum indentation depth of 2 nm, the indentation force is 540.89 nN along the cutting direction [ī00] and 651.70 nN along the cutting direction [ī01]. Table  4 compares the depths versus indentation depths in loading stage on the machining-induced surface along different cutting directions. Figure 11 Nanoindentation MD simulation load-displacement curves along different crystal directions, respectively.