Papers by Keyword: Micro-Cutting

Abstract: The cutting edge radius and cutting thickness as well as feed rate are in the same order of magnitude in micro-cutting. So it will appear a situation that the chip cannot be formed when the cutting thickness is less than a certain value which is the minimum cutting thickness. It is possible to find a method that can determine the minimum cutting thickness in the finite element simulation of micro-cutting according. In this paper, a series of finite element simulations of different workpiece materials in micro-cutting are carried out and several different minimum cutting thicknesses are obtained. It is shown that the minimum cutting thickness is related to the workpiece material in micro-cutting. When the workpiece materials are different, the minimum cutting thicknesses obtained are also different in micro-cutting.

Abstract: The wear performance and wear mechanism under two-body abrasion of five advanced high strength steels, i.e. Nanobainite (NB) steel, Tempered Martensitic (TM) steel, Dual Phase (DP) steel, Transformation Induced Plasticity (TRIP) Steel and Twining Induced Plasticity (TWIP) steel were studied. By using the scanning electron microscopy (SEM), we investigated the wearing surface. Phase transformation strengthening behavior was also be discussed by analyzing the surface and sub-surface after abrasion. The results showed that micro-cutting was the major role of wear mode in the condition of two-body abrasion. In the circumstance of two-body abrasion, hardness was an important factor, the property of wear resistance enhanced while the hardness increased except for TM steel. NB steel possessed the best wear resistance which was 1.71 times higher than that of TWIP steel. The retained austenite transformed into martensite which can improve the hardness so that it enhanced the wear resistance of NB steel.

Abstract: Stress analysis on wedge zone is an important step for micro-cutting tool design. The effect of stress borne by the cutting tool upon the radius of its blunt edge was analyzed, when the tool machines with minimum cutting thickness which is confined within 10-4-10-2mm. It shows that the minimal extreme value of the radius of blunt edge is existed in the process of micro-cutting tool design.

Abstract: In this paper, a finite element model with respect to actual state of micro-cutting is established by adopting software of ABAQUS/Explicit. Based on the FE model, the cutting force and specific cutting force with various uncut depth of cut with different cutting edge radius are compared and then analyzed with regard to this simulation. In micro-cutting, the nonlinear scaling phenomenon is more evident with the decreasing of uncut chip thickness. The likely explanations for the size effect in small uncut chip thickness are discussed in this paper.

Abstract: Considering the tribological characteristics of the micro-cutting, an approach that divided the micro-cutting area into four parts based on the contact stress and speed was proposed to the friction performance research. Friction tests under different conditions were carried out on a UMT3 tribometer and a special tribometer assembled based on HAWK TC-150 turning lathe. The morphological analyses of the worn surface were made by optical microscope and scanning electron microscope. The experimental results indicated that different rubbing pairs had different friction properties under different speeds or loads; for stainless steel, high speed steel showed a better friction performance in low speed and load, while cemented carbide has more advantages in high speed or high load. Hence, a suitable choice principle was proposed for the micro-cutting tool material based on the tribological characteristic.

Abstract: This study focuses on the nonlinear dynamic characteristics of tool vibration in ultra precision diamond turning. Considering the first mode vibration of a tool, the tool is modelled as a one degree of freedom spring-mass-damper system with a developed cutting force model. Numerical simulations were carried out to anlyze the nonlinear dynamics of the system, using bifurcation diagrams, Poincaré maps, phase protraits, time histories and power spectral densities. The results indicated that the dynamic response of the tool is dominantly periodic and harmonic at its natural frequency with a little negligible chaos and its natural frequency, more than its fundamental frequency, is slightly shifted by depth of cut and cutting force.

Abstract: In micro cutting field, the micro-cutting tool technology is one of the key technologies. Some new types of PCD milling tools have been designed and made. This paper presents an experimental investigation on micro-cutting pure tungsten to estimate PCD tool performance. Compare to commercial tungsten carbide helical tool, PCD tool can be used for micro-milling with wider ranges of processing parameters, and the material removal rate could be improved. The PCD tool worn mildly, and had longer tool life.

Abstract: Ultrasonic-vibration-assisted micro-cutting of Ti-6Al-4V was simulated by finite element analysis software ADVANTEDGE. During the micro-cutting of Ti-6Al-4V the cutting forces were compared between conventional and ultrasonic-vibration-assisted method. In the ultrasonic-vibration-assisted micro-cutting process different frequency and amplitude were applied on the cutting tool. The influences of frequency and amplitude were analyzed. The cutting temperature increases with the increase of the amplitude, and the cutting temperature decreases with the increase of frequency. By using the simulation method the appropriate amplitude and frequency data can be obtained.

Abstract: This paper analysis Griffith 's Theory and the metal theoretical fracture strength, thus introducing a line defect that existence in actual crystal — dislocation; And in-depth analysis the metal fracture dislocation mechanism in the micro cutting, and the formation and expand of the Fracture cracks , provides the theory basis for micro cutting

Abstract: It analyses deeply the diffrence between micro cutting and conventional machine cutting from the mechanism of cutting surface formation in this paper, and building the micro cutting model , then analyses friction mechanism of micro cutting processing introduce a new micro friction model, this paper discusses interface micro friction characteristics in the process of micro cutting.