دانلود کتاب A Magnetorheological-polishing-based approach for studying precision microground surfaces of tungsten carbides

توضیحاتی در مورد کتاب به زبان اصلی :

Статья. Опубликована в журнале "LLE Review". – 2005. – Vol. 105 – P. 51-62.Название на русском языке: Изучения на базе метода магнитореологического полирования прецизионного микрошлифования поверхности карбидов вольфрама.Аннотация к статье на английском языке:
We have studied the response of five nonmagnetic WC composites to deterministic microgrinding. Grinding experiments showed that grinding-induced surface roughness decreased with decreasing diamond abrasive size. Microgrinding with a rough tool (40-nm grit size) involved fracture, leading to a p–v surface roughness in the range of 3.2 to 5.8 nm (150- to 700-nm rms). Microgrinding with medium and fine tools (10- to 20-nm and 2- to 4-nm grit size, respectively) was controlled by plastic flow. The medium tool led to p–v surface roughness values in the range of 0.5 to 3.8 nm (27- to 200-nm rms), whereas the fine tool resulted in surface p–v values in the range of 53 to 86 nm (7- to 13-nm rms). The true grinding-induced surface roughness was concealed by the deformed layer on the ground surface. We have demonstrated that a MRF spot can be placed on ground surfaces of tungsten carbide and that the spot can be used to evaluate the depth of the surface deformed layer. For the rough and medium tools, the deformed layer is in the range 1.5- to 2.7-nm. The surface roughness of MRF spot at the deepest point of penetration can be used as a guide for establishing the optimal amount of material to be removed by MRF. Optimal MRF removal indeed removes the deformed surface layer caused by grinding. Excessive MRF removal may lead to preferential polishing and removal of the binder phase, also known as grain decoration. By utilizing both surface-roughness measurements and SEM imaging at the spot ddp, we were able to estimate the depth of the deformed layer. Thus, we showed that the depth of the deformed layer can be estimated in two ways. An optical profilometer-based measurement of the p–v surface microroughness of the ground surface provides an upper bound to the deformed layer thickness. This is a desirable estimate given the noncontact nature of this metrology technique. On the other hand, the MRF spot can also be used to reveal the depth of the deformed layer while reducing the surface roughness.