颗粒增强钛基复材缓进深切磨削加工研究
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摘要
颗粒增强钛基复合材料(PTMCs)属于典型的难加工材料,在航空航天领域具有广阔应用前景。本文开展了PTMCs材料的缓进深切磨削研究,揭示了磨削用量和磨削方式(顺磨与逆磨)对磨削力与磨削温度的影响规律,同时利用有限元法分析了磨削温度场特征和材料去除机理。研究发现,缓进深切磨削PTMCs时,磨削力随工件进给速度和切深增加而增加,顺磨时的磨削力比逆磨大10%~20%,而顺磨的磨削温度要比逆磨约低10%。由于逆磨和顺磨工件的温度分布不同,当切深大于0.6mm、工件进给速度大于400mm/min时,顺磨比逆磨更易发生烧伤。在此基础上,提出了顺磨与逆磨条件下磨削温度场仿真计算的不同热源模型与边界条件,分别获得了两种磨削方式的温度分布特征,有限元仿真结果与试验结果相符。颗粒增强钛基复材磨削表面典型加工缺陷是表面涂覆和硬脆增强相破碎和拔出导致的孔洞,单颗磨粒切厚对硬脆增强相的去除行为有显著的影响。
Particle-reinforced titanium matrix composites(PTMCs) has great application potentials in aviation and aerospace industries. However, it is a typical difficult-to-cut material. Creep-feed deep grinding experiments were carried out on PTMCs. The effect of grinding parameters and grinding mode on grinding forces and grinding temperatures was investigated. The grinding temperature distribution and materials removal mechanism were discussed by finite element method. The results show that the grinding forces increased with the increasing of the workpiece infeed speed and depth of cut. The grinding forces for down grinding are always 10%~20% higher than that for up grinding, the grinding temperatures for down grinding are always 10% lower than that for up grinding. When the depth of cut is greater than 0.6mm or the workpiece infeed speed is larger than 400mm/min, grinding burn is easy to occur for down grinding because the grinding temperature distribution is different between up grinding and down grinding. Furthermore, heat source model and the boundary condition under the down grinding and up grinding conditions are proposed, respectively. The grinding temperature distribution for two different grinding modes is simulated. The grinding temperature predicted by finite element method agrees very well with the experimental data measured in the current investigation. The main ground-induced defects are adherence and the voids produced due to the fracture and pull-out of the reinforced particles. The undeformed chip thickness per grain has a significant effect on the removal mechanism of the hard-brittle reinforcements of PTMCs during grinding.
Particle-reinforced titanium matrix composites(PTMCs) has great application potentials in aviation and aerospace industries. However, it is a typical difficult-to-cut material. Creep-feed deep grinding experiments were carried out on PTMCs. The effect of grinding parameters and grinding mode on grinding forces and grinding temperatures was investigated. The grinding temperature distribution and materials removal mechanism were discussed by finite element method. The results show that the grinding forces increased with the increasing of the workpiece infeed speed and depth of cut. The grinding forces for down grinding are always 10%~20% higher than that for up grinding, the grinding temperatures for down grinding are always 10% lower than that for up grinding. When the depth of cut is greater than 0.6mm or the workpiece infeed speed is larger than 400mm/min, grinding burn is easy to occur for down grinding because the grinding temperature distribution is different between up grinding and down grinding. Furthermore, heat source model and the boundary condition under the down grinding and up grinding conditions are proposed, respectively. The grinding temperature distribution for two different grinding modes is simulated. The grinding temperature predicted by finite element method agrees very well with the experimental data measured in the current investigation. The main ground-induced defects are adherence and the voids produced due to the fracture and pull-out of the reinforced particles. The undeformed chip thickness per grain has a significant effect on the removal mechanism of the hard-brittle reinforcements of PTMCs during grinding.
引文
[1]邓朝晖,万林林,张荣辉.难加工材料高效精密磨削技术研究进展[J].中国机械工程,2008,19(24):3018-3023.DENG Zhaohui,WAN Linlin,ZHANG Ronghui.Research progresses of high efficiency and precision grinding for hard to machine materials[J].China Mechanical Engineering,2008,19(24):3018-3023.
[2]GE Y F,XU J H,HUANG H X.Tool wear during high speed turning in situ,Ti Cp/Ti Bw,hybrid reinforced Ti-6Al-4V matrix composite[J].Chinese Journal of Aeronautics,2016,29(5):1425-1435.
[3]HOOD R,LECHNER F,ASPINWALL D K,et al.Creep feed grinding of gamma titanium aluminide and burn resistant titanium alloys using Si C abrasive[J].International Journal of Machine Tools&Manufacture,2007,47:1486-1492.
[4]DING W F,ZHAO B,XU J H,et al.Grinding behavior and surface appearance of(Ti Cp+Ti Bw)/Ti-6Al-4V titanium matrix composites[J].Chinese Journal of Aeronautics,2014,27:1334-1342.
[5]DOMAN D A,WARKENTIN A,BAUER R.Finite element modeling approaches in grinding[J].International Journal of Machine Tools&Manufacture,2009,49(2):109-116.
[6]MALKIN S,GUO C.Thermal analysis of grinding[J].CIRP Annals-Manufacturing Technology,2007,56(2):760-782.
[7]ROWE W B,JIN T.Temperatures in high efficiency deep grinding(HEDG)[J].CIRP Annals-Manufacturing Technology,2001,50(1):205-208.
[2]GE Y F,XU J H,HUANG H X.Tool wear during high speed turning in situ,Ti Cp/Ti Bw,hybrid reinforced Ti-6Al-4V matrix composite[J].Chinese Journal of Aeronautics,2016,29(5):1425-1435.
[3]HOOD R,LECHNER F,ASPINWALL D K,et al.Creep feed grinding of gamma titanium aluminide and burn resistant titanium alloys using Si C abrasive[J].International Journal of Machine Tools&Manufacture,2007,47:1486-1492.
[4]DING W F,ZHAO B,XU J H,et al.Grinding behavior and surface appearance of(Ti Cp+Ti Bw)/Ti-6Al-4V titanium matrix composites[J].Chinese Journal of Aeronautics,2014,27:1334-1342.
[5]DOMAN D A,WARKENTIN A,BAUER R.Finite element modeling approaches in grinding[J].International Journal of Machine Tools&Manufacture,2009,49(2):109-116.
[6]MALKIN S,GUO C.Thermal analysis of grinding[J].CIRP Annals-Manufacturing Technology,2007,56(2):760-782.
[7]ROWE W B,JIN T.Temperatures in high efficiency deep grinding(HEDG)[J].CIRP Annals-Manufacturing Technology,2001,50(1):205-208.