scholarly journals On the Role of Hollow Aluminium Oxide Microballoons during Machining of AZ31 Magnesium Syntactic Foam

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3534 ◽  
Author(s):  
Sathish Kannan ◽  
Salman Pervaiz ◽  
Abdulla Alhourani ◽  
Robert J. Klassen ◽  
Rajiv Selvam ◽  
...  

The role played by hollow ceramic thin-walled aluminium oxide microballoons on the shear deformation characteristics of AZ31 Magnesium syntactic foam is studied through high-speed machining. The ceramic microballoons embedded in the AZ31 matrix provides the necessary stiffness for these novel foams. The effect of hollow ceramic microballoon properties, such as the volume fraction, thin wall thickness to diameter ratio, and microballoon diameter, profoundly affects the chip formation. A novel force model has been proposed to explain the causes of variation in cutting forces during chip formation. The results showed an increase in machining forces during cutting AZ31 foams dispersed with higher volume fraction and finer microballoons. At a lower (Davg/h) ratio, the mode of microballoon deformation was a combination of bubble burst and fracture through an effective load transfer mechanism with the plastic AZ31 Mg matrix. The developed force model explained the key role played by AZ31 matrix/alumina microballoon on tool surface friction and showed a better agreement with measured machining forces.

2014 ◽  
Vol 800-801 ◽  
pp. 290-295
Author(s):  
Chuang Liu ◽  
Shu Tao Huang ◽  
Ke Ru Jiao ◽  
Li Fu Xu

Application prospect of the high volume fraction SiCp/Al composites becomes increasingly widespread, the study of cutting mechanism is important for achieving its high efficient and precision machining. In this paper, a three-dimensional beveled simulation model of high volume fraction SiCp/Al composites on high-speed milling is established by finite element software ABAQUS, the constitutive on model material, the tool-chip contact and the chip separation model is elected reasonably.The paper analyzes the effect of cutting speed on the chip formation and the stress distribution of the material. The results shows that: with the increasing of cutting speed, the chip is easily broken, cutting speed have little impact on the maximum stress of the material.


2020 ◽  
Vol 143 (3) ◽  
Author(s):  
S. Kannan ◽  
S. Pervaiz ◽  
R. J. Klassen ◽  
D. Huo ◽  
M. Haghshenas

Abstract Metal syntactic foams are a novel grade of materials that find potential applications in the manufacture of lightweight structural components and biomedical applications. For these materials to be inducted into industrial applications, it becomes imperative to study their machining behavior. In this article, for the first time in the literature, machining characteristics of AZ91 magnesium foam reinforced with thin-walled hollow alumina ceramic microspheres being studied. Through cutting experiments, it is found that finer the size of hollow microspheres and higher their volume fraction, higher was the magnitude of cutting forces recorded. The failure mechanisms that constituted chip formation during cutting AZ91 foam has been explicated through a mechanistic cutting force model. The proposed force model takes into account key hollow alumina microsphere properties such as wall thickness-to-diameter ratio, average microsphere size, and volume fraction. The scanning electron microscopic (SEM) analysis showed two key modes of failure during cutting metallic foams. Microsphere bursts and fractures control matrix plastic deformation through an effective load transfer mechanism. The transverse matrix cracks, which are initiated as a result of induced shear stress, promote the propagation of longitudinal adhesive cracks. This rapid crack growth takes place along the direction of maximum energy release rate, thus weakening the interfacial strength and reducing effective load transfer. This leads to microsphere separation, and further matrix densification due to the collapse of microsphere cavities leads to chip separation. The developed mechanistic model was in better agreement with experimental results.


2017 ◽  
Vol 882 ◽  
pp. 61-65
Author(s):  
Fadi Kahwash ◽  
Islam Shyha ◽  
Alireza Maheri

This paper presents an empirical force model quantifying the effect of fibre volume fraction and fibre orientation on the cutting forces during orthogonal cutting of unidirectional composites. Glass fibre plates and high speed steel cutting tools are used to perform orthogonal cutting on shaping machine whereas cutting forces are measured using platform force dynamometer. The analysis of forces shows almost linear dependency of cutting forces on the fibre content for both cutting and thrust forces. High dependency of cutting forces is also observed on fibre orientation with high percentage contribution ratio (up to 95.31%). Lowest forces corresponded to 30o and highest to 90o fibre orientation. Multivariate regression technique is used to construct the empirical model.


2011 ◽  
Vol 188 ◽  
pp. 3-8
Author(s):  
Shu Tao Huang ◽  
X.L. Yu ◽  
Li Zhou

SiCp/Al composites with high volume fraction and large particles are very difficult to machine. In this present study, high-speed milling experiments were carried out on the SiCp/Al composites by the three factors-levels orthogonal experiment method, and multiple linear regression analysis was employed to establish milling force model. The results show that the milling forces decrease with the increasing of the milling speed or increase with the increasing of the feed rate and depth of milling. The influence of milling depth on the milling forces in directions of x, y is the most significant, while the influence of the feed rate on the z-milling forces are the most significant. The calculation values from the milling force model are consistent with the experimental values. The results will provide a reliable theoretical guidance for milling of SiCp/Al composites, and it is feasible to predict the milling force during the milling of SiCp/Al by using this model.


Author(s):  
M. R. Pinnel ◽  
A. Lawley

Numerous phenomenological descriptions of the mechanical behavior of composite materials have been developed. There is now an urgent need to study and interpret deformation behavior, load transfer, and strain distribution, in terms of micromechanisms at the atomic level. One approach is to characterize dislocation substructure resulting from specific test conditions by the various techniques of transmission electron microscopy. The present paper describes a technique for the preparation of electron transparent composites of aluminum-stainless steel, such that examination of the matrix-fiber (wire), or interfacial region is possible. Dislocation substructures are currently under examination following tensile, compressive, and creep loading. The technique complements and extends the one other study in this area by Hancock.The composite examined was hot-pressed (argon atmosphere) 99.99% aluminum reinforced with 15% volume fraction stainless steel wire (0.006″ dia.).Foils were prepared so that the stainless steel wires run longitudinally in the plane of the specimen i.e. the electron beam is perpendicular to the axes of the wires. The initial step involves cutting slices ∼0.040″ in thickness on a diamond slitting wheel.


Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4143
Author(s):  
Youzheng Cui ◽  
Shenrou Gao ◽  
Fengjuan Wang ◽  
Qingming Hu ◽  
Cheng Xu ◽  
...  

Compared with other materials, high-volume fraction aluminum-based silicon carbide composites (hereinafter referred to as SiCp/Al) have many advantages, including high strength, small change in the expansion coefficient due to temperature, high wear resistance, high corrosion resistance, high fatigue resistance, low density, good dimensional stability, and thermal conductivity. SiCp/Al composites have been widely used in aerospace, ordnance, transportation service, precision instruments, and in many other fields. In this study, the ABAQUS/explicit large-scale finite element analysis platform was used to simulate the milling process of SiCp/Al composites. By changing the parameters of the tool angle, milling depth, and milling speed, the influence of these parameters on the cutting force, cutting temperature, cutting stress, and cutting chips was studied. Optimization of the parameters was based on the above change rules to obtain the best processing combination of parameters. Then, the causes of surface machining defects, such as deep pits, shallow pits, and bulges, were simulated and discussed. Finally, the best cutting parameters obtained through simulation analysis was the tool rake angle γ0 = 5°, tool clearance angle α0 = 5°, corner radius r = 0.4 mm, milling depth ap = 50 mm, and milling speed vc= 300 m/min. The optimal combination of milling parameters provides a theoretical basis for subsequent cutting.


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