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SURFACE structure, ENERGY gaps (Physics), LINEAR polarization, INFRARED lasers, ENERGY bands, and FEMTOSECOND lasers

Si is a semiconductor with a band gap energy of 1.12 eV, which corresponds to a wavelength of 1127.2 nm. Therefore, Si is considered as transparent for radiations longer than this wavelength. We have demonstrated that micromachining through an Si substrate by a femtosecond laser at 1552 nm is possible. We have found that periodic structures similar to the laser-induced periodic surface structure (LIPSS) with a periodicity of ~320 nm was formed on the back surface when the laser was focused on the back surface. The change of the surface was only observed on the back surface with no damage on the front surface. The LIPSS on the front surface were formed in perpendicular direction to the polarization plane of the laser while those on the back surface were always formed parallel to the polarization. The effects of laser irradiation conditions on the LIPSS have been studied. Furthermore, the LIPSS was found on the back surface after laser-assisted back-side wet etching by KOH solution, where the surface was in contact with water during irradiation. Both LSFL and HSFL were formed. Under some conditions, HFSL formed at center while LSFL formed on the edge of laser scan trace. [ABSTRACT FROM AUTHOR]

режущая пластина, стружкообразование, износ, задняя поверхность, составляющие силы резания, скорость резания, cutting plate, shaving, wear-out, back surface, forming power of the cutting, and velocity of the cutting

Исследования проводились в производственных и лабораторных условиях с использованием промышленного оборудования и современных измерительных средств. Установлена закономерность влияния дискретной режущей кромки на температуру резания, стойкость режущей пластины и силу резания при черновом точении материалов групп P и M.
The Studies were conducted in production and laboratory condition with use the industrial equipment and modern measuring facilities. The Installed regularity of the influence of the discrete cutting edge on the temperature of the cutting, stability of the cutting plate and power of the cutting at rough draft sharpening material of the groups P and M.

ленточки, drill bit, Cutting torque, drill, drilling, wear, Back surface, cutting speed, failure, limit state, сверло, момент сверления, сверление, износ, задняя поверхность, скорость резания, отказ, and предельное состояние

Показано, что функциональные отказы сверл обусловлены преимущественным изнашиванием задних поверхностей или ленточек инструмента в зависимости от диапазона скоростей резания. Достижение данных износов сопровождается возрастанием момента резания до критического значения. Получены зависимости для расчета предельно допустимых износов.
It is shown, that the failure of drills is generally conditioned by the wear of the back surfaces or the tool bits depending on the cutting speed. The subject wear factors cause increase in the cutting torque. The dependencies for calculating of the allowable wear rates for certain ranges of cutting speeds are obtained.

INTEGRATED circuits, DRILLING & boring, ALUMINUM alloys, METAL cutting, SURFACES (Technology), SCANNING electron microscopes, and OBSERVATION (Scientific method)

Chip formation during drilling operation is greatly influenced by the cutting parameters such as cutting speed, feed rate, and drill geometry. However, not many studies have focused on the direct observation of the chip formation during high speed drilling. This paper investigates the effect of cutting speed and feed rate on the chip morphology during high speed drilling of aluminum-silicon alloys using carbide drill. Observation on the multiview characterization of the chips was carried out which includes free surface, back surface, and cross-section of top surface. Structure and shape alterations of the free and back surfaces were analyzed using a scanning electron microscope. Finally, different geometrical parameters of chip cross-section were measured in order to study the effect of cutting parameters on chip compression ratio and thrust force. It was found that increase in cutting speed significantly affects the chip morphology especially on the structure of free surface and cross-section of the chips. Results also showed that built-up edge on the rake face of tool played an important role on the formation of irregular pattern on the chip back surface. [ABSTRACT FROM AUTHOR]

касательные напряжения, коэффициент трения, передняя поверхность, задняя поверхность, нитрид бора, высокотвердый материал, shear stress, Friction ratio, face surface, Back surface, boron nitride, and high-hardness material

Разработана упрощенная методика определения элементных показателей (напряжений и коэффициентов трения) на передней и задней поверхностях лезвия режущего инструмента, приведен пример расчета для процесса точения отбеленного чугуна и закаленной стали поликристаллическим кубическим нитридом бора.
Simplified method to find element factors (stress and friction ratio) on face and back surfaces of cutting tool end, is elaborated. Example to analyze cutting process of chilled iron and tampered steel by polycrystalline cubic boron nitride, is given.