Analytical Model of Cutting Force in Micromilling of Particle-Reinforced Metal Matrix Composites Considering Interface Failure

Author(s):  
Ben Deng ◽  
Lin Zhou ◽  
Fangyu Peng ◽  
Rong Yan ◽  
Minghui Yang ◽  
...  

During the micromachining processes of particle-reinforced metal matrix composites (PMMCs), matrix-particle interface failure plays an important role in the cutting mechanism. This paper presents a novel analytical model to predict the cutting forces in micromilling of this material considering particle debonding caused by interface failure. The particle debonding is observed not only in the processed surface but also in the chip. A new algorithm is proposed to estimate the particles debonding force caused by interface failure with the aid of Nardin–Schultz model. Then, several aspects of the cutting force generation mechanism are considered in this paper, including particles debonding force in the shear zone and build-up region, particles cracking force in the build-up region, shearing and ploughing forces of metal matrix, and varying sliding friction coefficients due to the reinforced particles in the chip-tool interface. The micro-slot milling experiments are carried out on a self-made three-axis high-precision machine tool, and the comparison between the predicted cutting forces and measured values shows that the proposed model can provide accurate prediction. Finally, the effects of interface failure, reinforced particles, and tool edge radius on cutting forces are investigated by the proposed model and some conclusions are given as follows: the particles debonding force caused by interface failure is significant and takes averagely about 23% of the cutting forces under the given cutting conditions; reinforced particles and edge radius can greatly affect the micromilling process of PMMCs.

Author(s):  
Zhichao Niu ◽  
Kai Cheng

The effects of cutting dynamics and the particles' size and density cannot be ignored in micro milling of metal matrix composites. This article presents the improved dynamic cutting force modelling for micro milling of metal matrix composites based on the previous analytical model. This comprehensive improved cutting force model, taking the influence of the tool run-out, actual chip thickness and resultant tool tip trajectory into account, is evaluated and validated through well-designed machining trials. A series of side milling experiments using straight flutes polycrystalline diamond end mills are carried out on the metal matrix composite workpiece under various cutting conditions. Subsequently, the measured cutting forces are compensated by a Kalman filter to achieve the accurate cutting forces. These are further compared with the predicted cutting forces to validate the proposed dynamic cutting force model. The experimental results indicate that the predicted and measured cutting forces in micro milling of metal matrix composites are in good agreement.


2015 ◽  
Vol 787 ◽  
pp. 637-642
Author(s):  
K. Jayakumar ◽  
Jose Mathew ◽  
M.A. Joseph

By considering several applications of aluminum based particle reinforced composites especially in automobile, aerospace and electronic industries, in this work, prediction of machinability responses of A356 alloy-SiC particles (5, 10, 15 and 20 vol%) reinforced metal matrix composites is described. Composites were synthesized by vacuum hot pressing (VHP) assisted powder metallurgy (P/M) process. Effect of cutting speed (Vc), feed (f), depth of cut (d) and quantity of SiC (vol %) on machinability of composites in terms of material removal rate (MRR) and resultant cutting forces (FR) during end milling were investigated. Milling experiments were carried in dry condition based on central composite design and KISTLER dynamometer was used to measure cutting forces. Resultant cutting force values were increased from 21 to 105 N with an increase in ‘f’ and ‘d’, but decreased with increase in ‘Vc’. Increase in machining parameters increased the MRR from 2.3 to 8.6 × 103 mm3/min and increase in SiC reduced the MRR. Statistical modeling with cubic response equations were used to predict the results and predicted results were closely matching with experimental values.


2013 ◽  
Vol 1 (1) ◽  
Author(s):  
Jian Liu ◽  
Juan Li ◽  
Chengying Xu

Due to its light weight, high creep, and wear resistance, magnesium metal matrix composites (Mg-MMCs) with nanosized reinforcements are promising for various industrial applications, especially those with high volume fractions of reinforcements. The machinability of Mg-MMCs and related cutting process modeling are important to study. In this paper, an analytical cutting force model is developed to predict cutting forces of Mg-MMC reinforced with SiC nanoparticles in micromilling process. This model is different from previous ones by encompassing the behaviors of nanoparticle reinforcements in three cutting scenarios, i.e., shearing, ploughing, and elastic recovery. By using the enhanced yield strength in the cutting force model, three major strengthening factors are incorporated, including load-bearing effect, enhanced dislocation density strengthening effect, and Orowan strengthening effect. In this way, material properties, such as the particle size and volume fraction as significant factors affecting the cutting forces, are explicitly considered. To validate the model, experiments based on various cutting conditions using two types of end mills (diameters as 100 μm and 1 mm) were conducted on pure Mg, Mg-MMCs with volume fractions of 5 vol. %, 10 vol. %, and 15 vol. %. The experimental results show a good agreement with the predicted cutting force value.


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