Authors: Han Ul Lee, Dong Woo Cho
Abstract: For effective rough milling, an optimized criterion is required to select the feedrate. In this
study, a method to obtain the most appropriate reference cutting force for rough milling was
developed. The reference cutting force was determined by considering the transverse rupture strength
of the tool material and the area of the rupture surface. A finite element method analysis was
performed to accurately calculate the area of the rupture surface. Using the analyzed results, the effect
of various cutting parameters on the chipping phenomenon was determined. The calculation method
for the reference cutting force considered the area of the rupture surface, the effect of the rake angle,
and the axial depth of cut. The experimental results clearly show that the reference cutting force
obtained from the proposed method met the desired constraints.
43
Authors: Zi Rui Pang, Suo Xian Yuan, Wan Shan Wang, Chun Xia Zhu
Abstract: In this paper, we emphasize that residual stresses in a ground surface are primarily
generated due to grinding zone temperature effect, and discuss grinding zone temperature can be
debased based on characteristics of the thin vitrified bond CBN wheel and quick-point grinding. Via
experimental results of 5 group working procedures, we find that surface roughness Ra showed a
tendency to reduce slightly with infeed rate reduced, cut depth increased, grinding wheel speed and
grinding variable angle increased, the favorable residual compressive stress could obtained along
with variables angle(α, β) increased, the sub-surface white etching layer and tempered martensite
layer in size become thinner with α, β angle and grinding wheel speed increased when removal rate
Z=0.06mm3/mm keep constant in quick-point grinding, by contraries, surface quality were
decreased entirely when variables angle(α, β) equal to zero. The results indicate it is important that
grinding variable angle were choice in quick-point grinding for to obtain favorable residual
compressive stress.
239
Authors: Yi Wan, Zhan Qiang Liu, Xing Ai
Abstract: Five-axis milling is widely used in machining of complex surfaces parts. Part quality and productivity are extremely affected by cutting force and tool wear, especially thin-walled complex surface, such as turbine blade. Although extensive research has been conducted on cutting force and tool wear in 3-milling process, very few are on 5-axis milling and bull-nose mills. This paper presents cutting forces with various cutting conditions as well as tool wear patterns in five-axis milling super alloy, which is essential to cutting vibration and defelction analysis of thin-walled complex surfaces parts. The roles of lead angle and tilt angle in five axis milling were investigated, which provide data for NC program edit. In addition, experiments in this research proved that tool wear played affected cutting forces outstandingly.Therefore, tool wear played an very important role in tool change.
2049
Authors: Jun Zhou, Jian Feng Li, Jie Sun
Abstract: In this paper, the micro-scale machining characteristics of a non-ferrous structural alloy, aluminum 7050-T7451 is investigated through a series of cutting experiments. The effects of cutting speed and undeformed chip thickness on the chip geometry, cutting ratio, effective rake angle and shear angle in orthogonal micro-scale cutting of Al 7075-T7451 are presented. Explanations for the observed trends are also given.
657
Authors: Atanu Das, Partha Pratim Saha, Santanu Das
Abstract: Shaping Burrs are produced at the edge of a workpiece when a cutter exits it. It causes difficulties in manufacturing and assembly stages. Several attempts were made to minimize burr to suppress deburring to improve productivity. Deburring of the surface in shaping operation in railways industry and other industries is a great problem. An investigation on burr formation at the exit edge of aluminum alloy (4600-M) flats in shaping operation is done in this work under dry environment. It is found out that burr is negligible at 150 exit edge bevel angle. Distribution of shear stress is analyzed using FEM to validate the experimental results. It is found that maximum equivalent stress and deformation at different points on the 150 exit edge bevel angle become minimum justifying the experimental observation. Hence, an exit edge bevel of 150 may be adopted to have minimum burr formation.
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