Study on formation mechanism of edge defects of high-volume fraction SiCp/Al composites by longitudinal-torsional ultrasonic vibration-assisted milling

Author(s):  
Daohui Xiang ◽  
Bo Li ◽  
Peicheng Peng ◽  
Zhanli Shi ◽  
Yanqin Li ◽  
...  

SiCp/Al composites are a kind of particle-reinforced composite material, which has been widely used in various fields due to its excellent performance. However, during the machining, the damage and failure of the SiC particles, the aluminum matrix, and the interface phase will cause many surface and edge defects. These defects will seriously affect the application of SiCp/Al composites. In this paper, a finite element model of randomly distributed multi-cell SiCp/Al composites with longitudinal-torsional ultrasonic vibration-assisted milling was established to analyze the formation mechanism of edge defects of the material. The simulation results showed that the main reason for the formation of edge defects was that the interface, SiC particles, and the Al matrix will produce cracks during machining, and these cracks will propagate and cause particle breakage, matrix tearing, and edge gaps. According to different machined parameters, the ultrasonic vibration-assisted milling experiment was carried out. The test results showed that the actual processed workpiece does have defects such as edge gaps. The depth of cut and the feed per tooth had a serious influence on the edge defect value, while the cutting speed had a small effect. Moreover, under the condition of applying appropriate ultrasonic amplitude, the phenomenon of edge defects and the surface quality were significantly improved. Therefore, the application of ultrasonic vibration-assisted milling can improve the surface and edge quality of SiCp/Al composites.

2020 ◽  
Vol 29 ◽  
pp. 2633366X2094252
Author(s):  
Yunan Liu ◽  
Shutao Huang ◽  
Keru Jiao ◽  
Lifu Xu

Thin-walled workpieces of silicon carbide particle-reinforced aluminum matrix (SiCp/Al) composites with outstanding properties have been widely applied in many fields, such as automobile, weapons, and aerospace. However, the thin-walled workpieces exhibit poor rigidity, large yield ratio, and easily deform under the cutting force and cutting heat during the machining process. Herein, in order to improve the processing efficiency and precision of higher volume fraction SiCp/Al composite thin-walled workpieces, the influence of different high-speed milling parameters and machining paths on the edge defects is analyzed. The results reveal that the cutting force initially increased and then decreased with the cutting speed. Besides, the cutting force steadily increased with radial cutting depth and feed per tooth, but the influence of feed per tooth is less than radial cutting depth. After up-milling cut-in and cut-out processing and down-milling cut-out processing, the cut-in end of the workpiece exhibited higher breakage and obvious edge defects. However, the workpiece edges remained intact after down-milling cut-in processing. In conclusion, a higher cutting speed, a smaller radial cutting depth, and moderate feed per tooth are required to decrease the cutting force during the milling of SiCp/Al composite thin-walled workpiece. Furthermore, down-milling cut-in processing mode can reduce the edge defects and improve the processing efficiency and precision of the workpiece.


2021 ◽  
Author(s):  
Guangyan Guo ◽  
Qi Gao ◽  
Quanzhao Wang ◽  
Yuanhe Hu

Abstract In order to improve the surface grinding quality of high volume fraction aluminum matrix composites, the cutting tool models with different rake angles are established, the grinding process is simulated, and the material removal mechanism and the broken state of SiC particles are obtained. Through single factor experiment, the 60% volume fraction SiCp/Al2024 composites are ground by diamond grinding rod with 3mm diameter, the surface roughness (Ra) is measured, and the surface and sub-surface quality of SiCp/Al2024 composites with meso-scale grinding is investigated. Meanwhile, the influence mechanism of grinding depth (ap) on surface quality is put forward, and the influence of different grinding depth on the fragmentation of SiC particles in sub-surface layer is discussed, which verifies the correctness of grinding simulation. The relevant research and theoretical model are of great significance to the study of grinding properties of composite materials.


Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3841 ◽  
Author(s):  
Zhang ◽  
Xiang ◽  
Wu ◽  
Feng ◽  
Shi ◽  
...  

Silicon carbide particle-reinforced aluminum matrix composite (SiCp/Al) has been widely used in the military and aerospace industry due to its special performance; however, there remain many problems in the processing. The present paper introduces an ultrasonic vibration tensile apparatus and a composite tensile specimen and performs Abaqus finite element simulation on high-volume SiCp/Al. The results show that the stress-strain curve increases linearly during conventional tensile strength; the intermittent vibration tensile strength is similar to the full course vibration tensile strength: The magnitude of the stress reduction increases as the amplitude of the ultrasound increases and the vibration frequency increases. The tensile rate is inversely proportional to the magnitude of the stress reduction, and in the ultrasonic parameters, the amplitude has the greatest influence on the magnitude of the stress reduction, followed by the tensile rate; additionally, the frequency has the least influence on the magnitude of the stress reduction. The experimental results show that the simulation results are consistent with the experimental results.


2015 ◽  
Vol 29 (06n07) ◽  
pp. 1540002 ◽  
Author(s):  
Dongfeng Cheng ◽  
Jitai Niu ◽  
Zeng Gao ◽  
Peng Wang

This experiment chooses A356 aluminum matrix composites containing 55% SiC particle reinforcing phase as the parent metal and Al – Si – Cu – Zn – Ni alloy metal as the filler metal. The brazing process is carried out in vacuum brazing furnace at the temperature of 550°C and 560°C for 3 min, respectively. The interfacial microstructures and fracture surfaces are investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy spectrum analysis (EDS). The result shows that adequacy of element diffusion are superior when brazing at 560°C, because of higher activity and liquidity. Dislocations and twins are observed at the interface between filler and composite due to the different expansion coefficient of the aluminum alloy matrix and SiC particles. The fracture analysis shows that the brittle fracture mainly located at interface of filler and composites.


2012 ◽  
Vol 723 ◽  
pp. 322-325
Author(s):  
Li Zhou ◽  
Shu Tao Huang ◽  
Da Shan Bai ◽  
Li Fu Xu

SiCp/Al composites have been used in a number of engineering applications including the consumer goods. However, the machining of these materials is very difficult because of the abrasive characteristics of the reinforced particulates. In this paper drilling studies on SiCp/Al composites with high volume fraction and large size SiC particles have been conducted by using electroplating diamond drills, and the influences of the cutting speed on the drilling force and surface roughness were investigated.


2021 ◽  
Author(s):  
Peicheng Peng ◽  
Daohui Xiang ◽  
Xiaofei Lei ◽  
Zhanli Shi ◽  
Bo Li ◽  
...  

Abstract Directing at the hard machinability of high volume fraction 70% SiCp/Al composites,a longitudinal and torsional ultrasonic-assisted milling method is proposed to improve the edge quality and machining efficiency. By observing the metallographic structure of the material, the three-dimensional finite element model of SiC particles with spherical, ellipsoidal and random polyhedra is established and analyzed by ABAQUS simulation software. The formation mechanism of edge defects, stress distribution, defect characteristics and the effect of machining parameters on milling force are investigated during ultrasonic-assisted milling. The results show that the edge defects appear at the inlet, outlet and middle edge position, especiallyis more serious at the outlet position. The SiC particles failure modes mainly include particle pullout, particle shearing, crushing, and the edge defects mainly include matrix tearing, edge breakage, burrs, bulgesandpits. In a certain range of ultrasonic amplitude, ultrasonic-assisted milling can effectively reduce the surface fragmentation rate and milling force, slow down the expansion of cracks, increase the plastic flow of material, and obtain better edge quality compared with traditional machining method. By comparing the results of finite element simulation and experimental tests, it shows that the simulation results are in good agreement with the experimental tests.


2021 ◽  
Author(s):  
Yongjie Bao ◽  
Xu Zhang ◽  
Shouxiang Lu ◽  
Hongzhe Zhang

Abstract SiC reinforced aluminum matrix composites (SiCp/Al composites) are typical difficult-to-machine material, and the irregular SiC particles diffused in SiCp/Al composites make the surface quality worse. In this paper, a single-point cutting investigations with finite element simulation were conducted for 65% SiCp/Al composites and aluminum alloy. The surface morphology characteristics of SiCp/Al composites, which mainly include breaking, part breaking, pulling out, protruding, al tearing, and interface debonding, are different from those of aluminum alloy materials. The high-volume SiC particles lower the surface quality and profile dimensional accuracy of SiCp/Al composites. There are thin and discrete layers covered on the machined surface.


2010 ◽  
Vol 455 ◽  
pp. 226-231 ◽  
Author(s):  
Shu Tao Huang ◽  
Li Zhou

The research on wear mechanism and characteristics of tool is a key issue for machining silicon carbide particle reinforced aluminum matrix composites (SiCp/Al). The machining adaptability, wear characteristics of the cermet cutting tools, TiN-coated tools and cemented carbide tools have been studied while milling SiCp/Al composites with large particle and high volume fraction. The results indicate that the wear resistance of the three kinds of tools are almost the same during machining large particle, high volume fraction SiCp/Al composite, and the tool wear is mainly presented as flank wear, which is caused by the mechanical wear of SiC particles. The wear rate of tools increases with increasing the cutting speed, but the difference is not very obvious. However, no matter high-speed cutting or low-speed cutting, the tool will be seriously worn in short distance. The each tooth cutter feed rate and depth of cutting have little effect on the tool wear.


2016 ◽  
Vol 836-837 ◽  
pp. 168-174 ◽  
Author(s):  
Ying Fei Ge ◽  
Hai Xiang Huan ◽  
Jiu Hua Xu

High-speed milling tests were performed on vol. (5%-8%) TiCp/TC4 composite in the speed range of 50-250 m/min using PCD tools to nvestigate the cutting temperature and the cutting forces. The results showed that radial depth of cut and cutting speed were the two significant influences that affected the cutting forces based on the Taguchi prediction. Increasing radial depth of cut and feed rate will increase the cutting force while increasing cutting speed will decrease the cutting force. Cutting force increased less than 5% when the reinforcement volume fraction in the composites increased from 0% to 8%. Radial depth of cut was the only significant influence factor on the cutting temperature. Cutting temperature increased with the increasing radial depth of cut, feed rate or cutting speed. The cutting temperature for the titanium composites was 40-90 °C higher than that for the TC4 matrix. However, the cutting temperature decreased by 4% when the reinforcement's volume fraction increased from 5% to 8%.


2017 ◽  
Vol 749 ◽  
pp. 107-110
Author(s):  
Yuta Masu ◽  
Tomohito Fukao ◽  
Taiga Yasuki ◽  
Masahiro Hagino ◽  
Takashi Inoue

The method of imparting ultrasonic vibration to the cutting tool is known to improve the shape accuracy and finished surface roughness. However, a uniform evaluation of this function in drilling has not been achieved, and the cutting process cannot be checked from the outside. The aim of this study is to investigate the cutting characteristics in deep hole drilling when an ultrasonic vibrator on the table of a machining center provides vibration with a frequency of 20 kHz to the work piece. The ultrasonic vibrations in this system reach the maximum amplitude in the center of the work material. We evaluated the change in finished surface roughness between the section where drilling starts to the point of maximum amplitude with ultrasonic vibration. The main cutting conditions are as follows: cutting speed (V) 12.6 (mm/min); feed rate (s) 30, 60 (mm/rev); depth of cut (t) = 32 (mm); work material, tool steel; cutting tool material, HSS; point angle (σ) 118 (°); and drill diameter (φ) 4 (mm). Lubricant powder was also added to clarify the cutting effect, and compared the condition in which there was no ultrasonic vibration. The results showed that surface roughness at the point of maximum amplitude was better than that with no vibration.


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