In order to study the surface integrity of superalloy GH4169 under high-speed milling, the rules governing the cutting surface morphology and microstructure of the superalloy are analyzed on the basis of the measurments of the variation of milling forces with the changes of the processing parameters and time during high-speed milling. The results indicate that in the range of the experimental parameters, the forces have a trend of first rising and then falling, and that they reach the peak when the cutting speed of end milling is 75.4 m/min. The surface roughness decreases with increasing cutting speed, but increases with increasing feed. Under the conditions of the experiment, a metamorphic layer appears at the milling surface generated by the major cutting edge, but the layer is hardly observed at the surface generated by vice cutting edge. The thickness of the metamorphic layer changes as the contact angle changes, and the thickest metamorphic layer is observed where the contact angle is about 120°. The thickness of the metamorphic layer has a trend of first rise and then fall as the cutting speed increases. The thickest metamorphic layer of end milling appears when the cutting speed is about 75.4 m/min, which is about 150.7 m/min of side milling. It is suggested that the thrust force plays the main mechanical role of forming the metamorphic layer, and that the coupled thermo-mechanical action during high-speed milling is the basic cause that generates the metamorphic layer.
DU Suigeng, WANG Zhibin, LU Chao, JU Jiangtao, ZHANG Jing
. Study on High-speed Milling Surface Microstructure of Superalloy[J]. ACTA AERONAUTICAET ASTRONAUTICA SINICA, 2011
, 32(6)
: 1156
-1163
.
DOI: CNKI:11-1929/V.20101228.1334.001
[1] Grzesik W. High speed machining[M]//Advanced Machining Processes of Metallic Materials. Elsevier, 2008: 213-226.
[2] 杜随更, 吕超, 任军学, 等. 钛合金TC4高速铣削表面形貌及表层组织研究[J]. 航空学报, 2008, 29(6): 1710-1715. Du Suigeng, Lu Chao, Ren Junxue, et al. Study on the high-speed milling surface morphology and microstructure of titanium alloy TC4[J]. Acta Aeronautica et Astronautica Sinica, 2008, 29(6): 1710-1715. (in Chinese)
[3] Bosheh S S, Mativenga P T. White layer formation in hard turning of H13 tool steel at high cutting speeds using CBN tooling[J]. International Journal of Machine Tools & Manufacture, 2006, 46(2): 225-233.
[4] Che-Haron C H, Jawaid A. The effect of machining on surface integrity of titanium alloy Ti-6%Al-4%V[J]. Journal of Materials Processing Technology, 2005, 166(2): 188-192.
[5] 邹金文, 汪武祥. 粉末高温合金研究进展与应用[J]. 航空材料学报, 2006, 26(3): 244-250. Zou Jinwen, Wang Wuxiang. Development and application of P/M superalloy[J]. Journal of Aeronautical Materials, 2006, 26(3): 244-250. (in Chinese)
[6] Ezugwu E O, Wang Z M, Machado A R. The machinability of nickel-based alloys: a review[J]. Journal of Materials Processing Technology, 1999, 86(1-3): 1-16.
[7] Pawade R S, Joshi S S, Brahmankar P K, et al. An investigation of cutting forces and surface damage in high-speed turning of Inconel 718[J]. Journal of Materials Processing Technology, 2007, 192-193: 139-146.
[8] Pawade R S, Joshi S S. Effect of machining parameters and cutting edge geometry on surface integrity of high-speed turned Inconel 718[J]. International Journal of Machine Tools & Manufacture, 2008, 48(1): 15-28.
[9] Thakur D G, Ramamoorthy B, Vijayaraghavan L. Study on the machinability characteristics of superalloy Inconel 718 during high speed turning[J]. Materials and Design, 2009, 30(5): 1718-1725.
[10] Barry J, Byrne G. TEM study on the surface white layer in two turned hardened steels[J]. Materials Science and Engineering A, 2002, 325(1-2): 356-364.
[11] Han S, Melkote S N, Haluska M S, et al, White layer formation due to phase transformation in orthogonal machining of AISI 1045 annealed steel[J]. Materials Science and Engineering, 2008, 488(1-2): 195-204.
[12] Chou Y K, Evans C J. White layers and thermal modeling of hard turned surfaces[J]. International Journal of Machine Tools & Manufacture, 1999, 39(12): 1863-1881.
[13] 庞俊忠, 王敏杰, 钱敏, 等. 高速立铣P20淬硬钢的切屑形态和切削力的试验研究[J]. 中国机械工程, 2008, 19(2): 170-173. Pang Junzhong, Wang Minjie, Qian Min, et al. Chip morphology and cutting forces in high speed milling of hardened P20 steel[J]. China Mechanical Engineer, 2008, 19(2): 170-173. (in Chinese)
[14] 陆爱华. 高温合金高速铣削温度的研究. 南京: 南京航空航天大学, 2008. Lu Aihua. Study on cutting temperature in high speed milling of superalloys. Nanjing: Nanjing University of Aeronautics and Astronautics, 2008. (in Chinese)
[15] 杨晓. 高速切削刀具的应用[J]. 工具技术,2004,38(9): 43-47. Yang Xiao. Application of high speed cutting tools[J]. Tool Engineering, 2004, 38(9): 43-47. (in Chinese)
[16] 陈明, 袁人炜, 凡孝勇, 等. 三维有限元分析在高速铣削温度研究中的应用[J]. 机械工程学报, 2002, 38(7): 76-79. Chen Ming, Yuan Renwei, Fan Xiaoyong, et al. Application of three dimensional finite element analysis in cutting temperature for high speed milling[J]. Chinese Journal of Mechanical Engineering. 2002, 38(7): 76-79. (in Chinese)
[17] 史兴宽, 杨巧凤, 张明贤, 等. 钛合金TC4高速铣削表面的温度场的研究[J]. 航空制造技术, 2002(1): 34-37. Shi Xingkuan, Yang Qiaofeng, Zhang Mingxian, et al. Study on surface temperature field of Ti alloy TC4 during high speed milling[J]. Aeronautical Manufacturing Technology, 2002(1): 34-37. (in Chinese)
[18] Sasahara H, Obikawa T, Shirakashi T. FEM analysis of cutting sequence effect on mechanical characteristics in machined layessr[J]. Journal of Materials Processing Technology, 1996, 62(4): 448-453.
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