【摘要】：激光打孔技術(shù)具有質(zhì)量高、柔性好,效率高、應(yīng)用廣的特性,在實(shí)際工業(yè)化生產(chǎn)應(yīng)用中,具有廣闊的應(yīng)用前景與較高的研究價(jià)值。本文采用單因素法對高溫合金脈沖激光沖擊和環(huán)切打孔技術(shù)進(jìn)行了系統(tǒng)的理論分析和實(shí)驗(yàn)研究。闡述了激光打孔的分類和激光環(huán)切打孔的基本原理�；趥鳠釋W(xué)基本理論,通過有限元軟件建立在高溫合金材料上進(jìn)行激光沖擊打孔和環(huán)切打孔的溫度場模型,采用APDL編程語言對沖擊打孔和環(huán)切打孔過程的數(shù)值仿真進(jìn)行程序編寫,并分別得到了沖擊打孔和環(huán)切打孔時(shí)隨脈沖個(gè)數(shù)變化的孔廓圖和溫度場分布圖,且求解出了沖擊打孔和環(huán)切打孔時(shí)不同脈沖個(gè)數(shù)作用下的孔深和不同脈沖能量下的上孔徑。在進(jìn)行數(shù)值仿真后,比較沖擊打孔和環(huán)切打孔過程中溫度、孔深以及孔徑的變化。結(jié)果表明:沖擊孔和環(huán)切孔的深度都隨著脈沖個(gè)數(shù)的增加而上升,沖擊孔和環(huán)切孔的上孔徑都隨著脈沖能量的增加而增加,這與打孔實(shí)驗(yàn)結(jié)果一致。使用DMG數(shù)控精密激光加工中心的設(shè)備在高溫合金GH4037上分別進(jìn)行激光沖擊打孔實(shí)驗(yàn)和激光環(huán)切打孔實(shí)驗(yàn),系統(tǒng)地研究了脈沖能量、重復(fù)頻率、脈沖寬度、輔助氣體壓力對激光沖擊打孔質(zhì)量的影響以及環(huán)切圈數(shù)、重復(fù)頻率、輔助氣體壓力、脈沖寬度、脈沖能量、環(huán)切速度對激光環(huán)切打孔質(zhì)量的影響。實(shí)驗(yàn)中評定質(zhì)量的指標(biāo)包括:微孔表面形貌、孔徑尺寸、孔形、錐度和圓度等。沖擊打孔實(shí)驗(yàn)得出的結(jié)論表明:激光脈沖能量對沖擊孔孔徑和孔圓度影響最顯著,當(dāng)脈沖能量為1J,重復(fù)頻率為70Hz,脈沖寬度0.3ms,輔助氣體壓力0.4MPa時(shí)沖擊打孔的質(zhì)量較好�？椎娜肟趫A度比孔的出口圓度好。環(huán)切打孔實(shí)驗(yàn)結(jié)果表明:環(huán)切圈數(shù)和環(huán)切速度對孔徑的影響不大,適當(dāng)?shù)沫h(huán)切圈數(shù)、較小的環(huán)切速度使得微孔的表面質(zhì)量比較好。當(dāng)脈沖能量為1J,重復(fù)頻率為50Hz~70Hz,脈沖寬度0.3ms,輔助氣體壓力0.4MPa時(shí)環(huán)切打孔的質(zhì)量比較好。與沖擊打孔規(guī)律一致:脈沖能量對微孔孔徑和孔圓度影響最顯著,孔的入口圓度優(yōu)于孔的出口圓度。最后進(jìn)行激光環(huán)切斜孔的實(shí)驗(yàn),將環(huán)切打孔和斜孔的加工結(jié)合起來,驗(yàn)證在傾斜面上加工孔的可行性。
[Abstract]:Laser drilling technology has the characteristics of high quality, good flexibility, high efficiency and wide application. It has broad application prospect and high research value in practical industrial production. In this paper, single factor method is used for theoretical analysis and experimental study of pulsed laser impact and annular drilling of superalloy. The classification of laser drilling and the basic principle of laser ring drilling are described. Based on the basic theory of heat transfer, the temperature field model of laser impact drilling and ring cutting drilling on superalloy materials was established by finite element software. The APDL programming language is used to program the numerical simulation of impact drilling and annular drilling, and the hole profiles and temperature field distributions with the number of pulses are obtained, respectively. The hole depth under the action of different pulse number and the upper aperture under different pulse energy are obtained. After numerical simulation, the changes of temperature, hole depth and pore diameter during impact drilling and annular drilling were compared. The results show that the depth of impact hole and annular hole increase with the increase of pulse number, and the upper aperture of impact hole and annular hole increase with the increase of pulse energy, which is consistent with the experimental results. Using the equipment of DMG NC precision laser machining center, the laser shock drilling experiment and laser ring cutting experiment were carried out on superalloy GH4037. The pulse energy, repetition rate and pulse width were studied systematically. The influence of auxiliary gas pressure on the quality of laser impact drilling and the influence of ring tangent ring number, repetition rate, auxiliary gas pressure, pulse width, pulse energy and ring cutting speed on the quality of laser ring cut hole. The indexes of quality evaluation include: surface morphology, pore size, pore shape, taper and roundness. The results of the impact drilling experiment show that the laser pulse energy has the most significant effect on the aperture and roundness of the impact hole. When the pulse energy is 1 J, the repetition rate is 70 Hz, the pulse width is 0.3 Ms and the auxiliary gas pressure is 0.4MPa, the quality of the impact drilling is better. The roundness of the inlet of the hole is better than the roundness of the outlet of the hole. The experimental results show that the ring tangent ring number and the ring cutting speed have little effect on the aperture. The surface quality of the microhole is better because of the proper ring cutting circle number and the smaller ring cutting speed. When the pulse energy is 1J, the repetition rate is 50Hz, the pulse width is 0.3msand the auxiliary gas pressure is 0.4MPa, the quality of annular perforation is better. The effect of pulse energy on pore diameter and pore roundness is the most significant, and the roundness of the inlet of the hole is better than that of the outlet of the hole. Finally, the experiment of laser annular slant hole cutting is carried out, and the feasibility of drilling hole on inclined plane is verified by combining the annular hole cutting with the oblique hole machining.
【學(xué)位授予單位】：江蘇大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TG132.3;TG665

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本文編號：2274271