Research on the underlying mechanism behind abrasive flow machining on micro-slit structures and simulation of viscoelastic media

Abstract

In this study, the machining mechanism of abrasive flow machining (AFM) microstructures was analyzed in depth according to the transmission morphology and rheological behaviors of the abrasive media. The transmission morphology demonstrated the excellent combination of the polymer melt with abrasive grains at the interface, indicating that the polymer melt, combined with the uniform distribution of the polymer chains, could exert a harmonious axial force on the abrasive grains. Based on the rheological behavior analysis of the abrasive media, for example, the stress relaxation and moduli of storage and loss, a machining mechanism model was established incorporating the effect of microplastic deformation and continuous viscous flow, which was further verified by the grooves along the flow direction. In addition, the Phan-Thien-Tanner (PTT) model combined with a wall slipping model was employed to simulate the machining process for the first time here. The value of the simulated pressure (1.3 MPa) was similar to the measured pressure (1.45 MPa), as well as the simulated volumetric rate (0.011 4 mL/s) to the measured volumetric rate (0.067 mL/s), which further proved the validity of the simulation results. The flow duration (21 s) derived from a velocity of 1.2 mm/s further confirmed the residual stretched state of the polymer chains, which favored the elasticity of the abrasive media on the grains. Meanwhile, the roughly uniform distribution of the shear rate at the main machining region exhibited the advantages of evenly spread storage and loss moduli, contributing to the even extension of indentation caused by the grains on the target surface, which agreed with the mechanism model and machined surface morphology.

Keywords

Abrasive flow machining (AFM) / Microstructure / Machining mechanism / Phan-Thien-Tanner (PTT) model / Experimental verification

References

[1] Miao J, Fan Y, Wu W. Effects of nozzle configuration on flash boiling fuel sprays of twin-orifice nozzle with aviation kerosene. Int J Heat Mass Tran, 2021, 174.

[2] Oliver TA, Bogard DG, Moser RD. Large eddy simulation of compressible, shaped-hole film cooling. Int J Heat Mass Tran, 2019, 140: 498-517.

[3] Singh S, Kumar D, Ravi Sankar M, et al. Nanofinishing of microslots on surgical stainless steel by abrasive flow finishing process: experimentation and modeling. J Micro Nano-Manuf, 2018, 6(2): .

[4] Mirjavadi SS, Alipour M, Hamouda AMS, et al. Effect of multi-pass friction stir processing on the microstructure, mechanical and wear properties of AA5083/ZrO₂ nanocomposites. J Alloy Compd, 2017, 726: 1262-1273.

[5] Gorana VK, Jain VK, Lal GK. Prediction of surface roughness during abrasive flow machining. Int J Adv Manuf Technol, 2006, 31(3): 258-267.

[6] Rhoades L. Abrasive flow machining: a case study. J Mater Process Technol, 1991, 28(1): 107-116.

[7] Jain RK, Jain VK, Dixit PM. Modeling of material removal and surface roughness in abrasive flow machining process. Int J Mach Tools Manuf, 1999, 39(12): 1903-1923.

[8] Singh S, Shan HS, Kumar P. Experimental studies on mechanism of material removal in abrasive flow machining process. Mater Manuf Process, 2008, 23(7): 714-718.

[9] Jain VK, Adsul SG. Experimental investigations into abrasive flow machining (AFM). Int J Mach Tools Manuf, 2000, 40(7): 1003-1021.

[10] Gorana VK, Jain VK, Lal GK. Experimental investigation into cutting forces and active grain density during abrasive flow machining. Int J Mach Tools Manuf, 2004, 44(2): 201-211.

[11] Munhoz MR, Dias LG, Breganon R, et al. Analysis of the surface roughness obtained by the abrasive flow machining process using an abrasive paste with oiticica oil. Int J Adv Manuf Tech, 2020, 106(11/12): 5061-5070.

[12] Bremerstein T, Potthoff A, Michaelis A, et al. Wear of abrasive media and its effect on abrasive flow machining results. Wear, 2015, 342: 44-51.

[13] Sankar RM, Jain VK, Ramkumar J, et al. Rheological characterization of styrene-butadiene based medium and its finishing performance using rotational abrasive flow finishing process. Int J Adv Manuf Tech, 2011, 51(12): 947-957.

[14] Dong Z, Ya G, Liu J. Study on machining mechanism of high viscoelastic abrasive flow machining for surface finishing. P I Mech Eng B-J Eng Manuf, 2017, 231(4): 608-617.

[15] Tan DP, Ji SM, Fu YZ. An improved soft abrasive flow finishing method based on fluid collision theory. Int J Adv Manuf Tech, 2016, 85(5): 1261-1274.

[16] Chen F, Hao S, Miao X, et al. Numerical and experimental study on low-pressure abrasive flow polishing of rectangular microgroove. Powder Tech, 2018, 327: 215-222.

[17] Wan S, Ang YJ, Sato T, et al. Process modeling and CFD simulation of two-way abrasive flow machining. Int J Adv Manuf Tech, 2014, 71(5): 1077-1086.

[18] Wang AC, Tsai L, Liang KZ, et al. Uniform surface polished method of complex holes in abrasive flow machining. T Nonferr Metal Soc, 2009, 19(1): s250-s257.

[19] Uhlmann E, Schmiedel C, Wendler J. CFD simulation of the abrasive flow machining process. Procedia CIRP, 2015, 31: 209-214.

[20] Fu Y, Gao H, Yan Q, et al. Rheological characterisation of abrasive media and finishing behaviours in abrasive flow machining. Int J Adv Manuf Tech, 2020, 107(7/8): 3569-3580.

[21] Bowden FP, Moore AJW, Tabor D. The ploughing and adhesion of sliding metals. J Appl Phys, 1943, 14(2): 80-91.

Funding

National Natural Science Foundation of China http://dx.doi.org/10.13039/501100001809(52175423)

Guangdong Key Laboratory of Precision Equipment and Manufacturing Technology http://dx.doi.org/10.13039/501100011524(2020B010185001)

Huohua Project (20-163-00-TS-009-159-01)

Shanghai Municipal Human Resources and Social Security Bureau-Pujiang Program (2019PJD021)