Effect of anisotropy and cutting speed on chip morphology of Ti-6Al-4V under high-speed cutting

2021 ◽  
Vol 113 (9-10) ◽  
pp. 2883-2894
Author(s):  
Qihang Shi ◽  
Yongzhi Pan ◽  
Xiuli Fu ◽  
Bin Zhou ◽  
Zewen Zhang
Author(s):  
Zengqiang Wang ◽  
Zhanfei Zhang ◽  
Wenhu Wang ◽  
Ruisong Jiang ◽  
Kunyang Lin ◽  
...  

Abstract High speed cutting (HSC) technology has the characteristics of high material removal rates and high machining precision. In order to study the relationships between chip morphology and machining surface characteristic in high speed cutting of superalloy Inconel718. High-speed orthogonal cutting experiment are carried out by used a high speed cutting device based on split Hopkinson pressure bar (SHPB). The specimen surfaces and collected chips were then detected with optical microscope, scanning electron microscope and three-dimensional surface profile measuring instrument. The results show that within the experimental parameters (cutting speed from 8–16m/s, depth of cut 0.1–0.5mm), the obtained chips are sawtooth chips and periodic micro-ripple appear on the machined surface. With the cutting speed increases, machining surface roughness is decreases from 1.4 to 0.99μm, and the amplitude of periodic ripples also decreases. With the cutting depth increases, the machining surface roughness increases from 0.96 to 5.12μm and surface topography becomes worse. With the increase of cutting speed and depth of cut, the chips are transform from continues sawtooth to sawtooth fragment. By comparing the frequency of surface ripples and sawtooth chips, it is found that they are highly consistent.


2009 ◽  
Vol 626-627 ◽  
pp. 65-70
Author(s):  
Hui Ping Zhang ◽  
X.P. Ji ◽  
Jue Wang ◽  
Er Liang Liu

This paper deals with the effect of cutting speed on chip fracture strain in high speed cutting. Firstly, a chip-fracture-strain-measuring device is designed and made according to chip breaking principle. Secondly, experiments are performed by the chip-fracture-strain-measuring device. The experiment results show that chip fracture strain increases first and then diminishes as cutting speed increasing in high speed cutting while feedrate and depth of cut are constant values. Lastly, the effect of cutting speed on chip fracture strain is theoretically analysed from three main factors which affect chip fracture strain. The study above lays a theory and basis for future investigation of chip fracture strain of the other metals and for future investigation the mechanism and chip breaking forecast system of 3-D groove insert in high speed cutting.


2010 ◽  
Vol 26-28 ◽  
pp. 875-879
Author(s):  
Chun Zheng Duan ◽  
Hong Hua Li ◽  
Min Jie Wang ◽  
Yu Jun Cai

The chip morphology and the formation and development of the adiabatic shear band within the serrated chips formed in high speed cutting of 30CrNi3MoV steel with two tempering hardness were observed and analyzed using optical microscope and SEM. The investigation shows that as the adiabatic shear phenomenon occurs and develops, the chip morphology changes as follows: ribbon chip→serrated chip with deformed band→serrated chip with transformed band→fractured chip. The cutting speed and tempering hardness is the two main factors affecting adiabatic shear, in the case of lower cutting speed the formation and development of adiabatic shear band are more sensitive to tempered hardness increase. The deformed shear bands are constituted by large deformed microstructure, while the formation of the transformed shear bands has experienced the large plastic deformation and grain refinement.


2007 ◽  
Vol 10-12 ◽  
pp. 359-363 ◽  
Author(s):  
Dong Jin Zhang ◽  
Gang Liu ◽  
X. Sun ◽  
Ming Chen

The nickel-based superalloy GH4169 is a typical difficult-to-cut material, but it has been used in a good many kinds of aeronautical key structures because of its high yield stress and anti-fatigue performance at the temperature below 650°C. In this paper, finite element method (FEM) was introduced to study the saw-tooth chip forming process in detail when machining nickel-based superalloy GH4169. By the way of Lagrangian visco-elastic plastic approach, adiabatic shear band (ASB) was simulated in high speed machining condition by general commercial finite element code, and the mechanism of the adiabatic shearing phenomenon at primary shear zone was analyzed with the help of finite element analysis (FEA). The comprehensive comparisons of saw-tooth chip morphology under a wide range of cutting speed were also presented.


2011 ◽  
Vol 287-290 ◽  
pp. 104-107
Author(s):  
Lian Qing Ji ◽  
Kun Liu

The history and application of the FEA are briefly presented in this paper. Several key technologies such as the building of material model, the establishment of the chip - tool friction model as well as meshing are described. Taking the high-speed cutting of titanium alloy (Ti - 10V - 2Fe - 3Al) as an example , reasonable cutting tools and cutting parameters are determinted by simulating the influences of cutting speed, cutting depth and feeding rate on the cutting parameters using FEA.


2009 ◽  
Vol 407-408 ◽  
pp. 420-423
Author(s):  
He Ping Wang ◽  
Xue Ping Zhang

An explicit dynamic coupled thermal-mechanical Arbitrary Lagrangian Eulerian (ALE) model was established to simulate orthogonal cutting AISI 52100 bearing steel, and its temperature and stress distribution. Based on ABAQUS, The ALE approach effectively simulates plastic flow around round edge of the cutting tool without employing chip separation criteria. The calculation results reveal that cutting speed and cutting depth have great impact on chip morphology, stress and temperature distribution in the finished surface and subsurface, the predicted temperature agrees well with experiment data obtained under the similar cutting conditions as well as the change in chip morphology from continuous to sawtooth as the cutting speed increases.


Author(s):  
Jae-Wook Oh ◽  
Hsin-Yu Kuo ◽  
Kevin Meyer ◽  
Roger Lindle ◽  
Howard Weaver ◽  
...  

At some cutting conditions chips formed during high-speed face turning of nickel based alloys are re-bonded to the machined workpiece surface, even when coolant is applied. Unfortunately, chip-rebonding reduces surface quality, which leads to a shorter fatigue lives for machined parts. Although several researchers have documented this phenomenon and its effects, the root causes of this phenomenon is currently unknown. In order to determine the root causes of chip rebonding, past test samples exhibiting chip rebonding were first analyzed. Metallographic analysis revealed that the chip rebonding material is the same as the workpiece material and that the bonding is mechanically driven. Next, screening design of experiments (DOE) were completed to reliably reproduce chip rebonding in dry cutting cases. Chip rebonding detection and severity were measured using multiple equally spaced surface roughness measurements (Rt parameter). In addition, in-process cutting forces and tool wear measurements were recorded and compared. Finally Taguchi methods were applied to identify the key variables their influence on chip-rebonding. In dry cutting tests it was found that decreasing feed-rate while cutting at a constant cutting speed is the most influential factor in obtaining chip rebonding. High-speed video revealed that at lower feed-rates the chip curls back to the surface of workpiece, while at higher feed-rates the chip flows away from the cutting region with minimal curl. Additional testing performed verifies this theory.


Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 1020
Author(s):  
Xu Zhang ◽  
Guangming Zheng ◽  
Xiang Cheng ◽  
Rufeng Xu ◽  
Guoyong Zhao ◽  
...  

Considering that iron-based super alloy is a kind of difficult-to-cut material, it is easy to produce work hardening and serious tool wear during machining. Therefore, this work aims to explore the chip change characteristics and tool wear mechanism during the processing of iron-based super alloy, calculate the fractal dimensions of chip morphology and tool wear morphology, and use fractals to analyze their change trend. Meanwhile, a new cutting tool with a super ZX coating is used for a high-speed dry turning experiment. The results indicate that the morphology of the chip is saw-tooth, and its color changes gradually, due to the oxidation reaction. The main wear mechanisms of the tool involve abrasive wear, adhesive wear, oxidation wear, coating spalling, microcracking and chipping. The fractal dimension of the tool wear surface and chip is increased with the improvement of cutting speed. This work investigates the fractal characteristics of chip morphology and tool wear morphology. The fractal dimension changes regularly with the change of tool wear, which plays an important role in predicting this tool wear. It is also provides some guidance for the efficient processing of an iron-based super alloy.


Author(s):  
Zhanfei Zhang ◽  
Zengqiang Wang ◽  
Wenhu Wang ◽  
Ruisong Jiang ◽  
Yifeng Xiong

High-speed cutting technology has the characteristics of high material removal rate and excellent processing quality. To investigate the surface quality of high-speed cutting Ti6Al4V alloy, the orthogonal cutting experiment is the cutting device based on improved Split-Hopkinson pressure bar carried out with a cutting speed of about 7–16 m/s. Surface roughness, residual stress and three-dimensional surface topography are examined to characterize the surface quality. And the chip geometry parameters are measured to analyze the formation mechanism of surface topography. The result shows that cutting force and surface roughness increase rapidly with the increase in depth of cut. In the meantime, the periodic microwaves appeared on the machined surface, and their amplitudes increase with the increase in depth of cut. However, surface roughness, residual stress and microwave amplitude all decrease with the increase in cutting speed. Moreover, it is found that the evolution trend of chip thickness and surface roughness with cutting parameters is very similar. Therefore, it can be inferred that there is a strong relationship between surface topography and chip morphology.


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