發(fā)布時間：2018-12-30 10:21

【摘要】：GH4169合金具有良好的高溫力學(xué)性能、較強的熱腐蝕抗力以及優(yōu)異的高溫抗氧化性,已廣泛應(yīng)用于航空航天領(lǐng)域。然而,GH4169合金硬度不高、抗疲勞強度一般,限制了其在航空結(jié)構(gòu)件中的進(jìn)一步應(yīng)用。本文通過對GH4169合金進(jìn)行高能噴丸處理,研究了噴丸時間和彈丸尺寸對合金表面狀態(tài)、表面粗糙度、顯微硬度、殘余應(yīng)力和表層組織的影響,對比了干噴丸和濕噴丸下合金表層組織和性能差異,探究了GH4169合金噴丸強化機(jī)理,獲得了以下結(jié)論:GH4169合金干噴丸處理后表面缺陷增多,表面完整性下降。1mm和2mm彈丸噴丸后,試樣表面缺陷主要表現(xiàn)為翹曲,起皮和塌陷。而4mm彈丸噴丸后,試樣表面缺陷主要表現(xiàn)為長條狀和多邊形狀缺陷。干噴丸處理后GH4169合金表面粗糙度、顯微硬度和殘余應(yīng)力都顯著提升。其中1mm彈丸噴丸3min時,表面粗糙度最小,為2.857μm;4mm彈丸噴丸10min時,表面顯微硬度提升最大,為401HV,較原始試樣硬度(289HV)提升了39%;隨著噴丸時間延長,表層殘余應(yīng)力場強度增加,1mm彈丸噴丸10min時,表層最大殘余應(yīng)力達(dá)到了-684MPa。XRD分析結(jié)果顯示,GH4169合金噴丸后試樣表層無相變發(fā)生,且隨著噴丸時間和彈丸尺寸增加,衍射峰的強度降低,半高寬逐漸增大,表明組織細(xì)化程度增加。此外,隨著噴丸時間和彈丸尺寸增大,噴丸作用層厚度不斷增加。4mm彈丸噴丸10min時,噴丸作用層厚度最大,達(dá)到450μm。與干噴丸相比,濕噴丸后試樣表面缺陷明顯減少,表面缺陷主要表現(xiàn)為起皮。且隨著彈丸尺寸增大,水對彈丸的緩沖和潤滑作用更顯著,對材料表面完整性的保護(hù)程度也越高。濕噴丸后試樣表面粗糙度較干噴丸相比顯著降低,2mm彈丸噴丸10min時,表面粗糙度降低幅度最大,達(dá)到了53%。此外,與干噴丸相比,濕噴丸后試樣表面殘余應(yīng)力更大,2mm彈丸噴丸10min時,表面殘余應(yīng)力提升了9%左右。GH4169合金經(jīng)噴丸后,表層形成了較強的殘余應(yīng)力場,表層晶粒內(nèi)部出現(xiàn)了大量的形變孿晶,且距離噴丸面越近,多系孿晶間的相互交割現(xiàn)象也越明顯,孿晶數(shù)量越多,組織細(xì)化程度越高。因此,GH4169合金干噴丸和濕噴丸的表面強化都是由表層組織細(xì)化、形變孿晶形成以及殘余應(yīng)力強化等因素綜合作用的結(jié)果。
[Abstract]:GH4169 alloys have been widely used in aerospace industry due to their good mechanical properties at high temperature, strong thermal corrosion resistance and excellent high temperature oxidation resistance. However, the hardness and fatigue strength of GH4169 alloy are not high, which limits its further application in aeronautical structure. The effects of shot peening time and projectile size on the surface state, surface roughness, microhardness, residual stress and surface microstructure of GH4169 alloy were studied in this paper. The microstructure and properties of the alloy under dry and wet shot peening were compared, and the mechanism of shot peening strengthening of GH4169 alloy was investigated. The following conclusions were obtained: the surface defects increased and the surface integrity decreased after shot peening of GH4169 alloy. After shot peening by 1mm and 2mm, the surface defects increased and the surface integrity decreased after shot peening with 1mm and 2mm. The surface defects of the sample mainly show warping, peeling and collapse. However, after 4mm shot peening, the surface defects of the samples were mainly strip and multilateral shape defects. The surface roughness, microhardness and residual stress of GH4169 alloy were improved after shot peening. When 1mm shot peening 3min, the surface roughness was the smallest, and when shot peening 10min was 2.857 渭 m or 4mm, the surface microhardness was the highest, which was 401 HV. the surface roughness was 39% higher than that of the original sample (289HV). With the prolongation of shot peening time, the intensity of surface residual stress field increases. When 1mm shot peening 10min, the maximum residual stress of the surface layer reaches-684MPa.XRD analysis results show that there is no phase change in the surface layer of GH4169 alloy after peening. With the increase of shot peening time and projectile size, the intensity of diffraction peak decreases and the half-maximum width increases, which indicates that the degree of microstructure refinement increases. In addition, with the increase of shot peening time and shot size, the thickness of the action layer of shot peening increases continuously. When 4mm shot peening 10min, the thickness of shot peening layer is the largest, reaching 450 渭 m. Compared with dry shot peening, the surface defects of wet shot peening samples were obviously reduced, and the surface defects were mainly peeled. With the increase of the size of the projectile, the buffering and lubricating effect of water on the projectile is more obvious, and the protection degree of the surface integrity of the material is also higher. After wet shot peening, the surface roughness of the sample was significantly lower than that of dry shot peening. When 2mm shot peening 10min, the surface roughness of the sample decreased to 53%. In addition, compared with dry shot peening, the residual stress on the surface of wet shot peening is greater than that of dry shot peening. When 2mm shot peening 10min, the surface residual stress increases by about 9%. After shot peening, a strong residual stress field is formed on the surface of GH4169 alloy. There are a large number of deformation twins in the surface grain, and the closer to the shot peening surface, the more obvious the intersecting phenomenon between the multi-system twins is, and the more the number of twins is, the higher the degree of microstructure refinement is. Therefore, the surface strengthening of GH4169 alloy by dry shot peening and wet shot peening is the result of the combined effect of surface microstructure refinement, deformation twin formation and residual stress strengthening.
【學(xué)位授予單位】：南昌航空大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TG668

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 梁爽;劉智鑫;李秋鶴;;鎳基高溫合金的發(fā)展綜述[J];山東工業(yè)技術(shù);2016年04期

2 王欣;胡仁高;胡博;湯智慧;羅學(xué)昆;;噴丸強化對GH4169合金孔結(jié)構(gòu)高溫低周疲勞性能的影響[J];中國表面工程;2015年06期

3 韓志宇;曾光;梁書錦;陳小林;張鵬;張平祥;;鎳基高溫合金粉末制備技術(shù)的發(fā)展現(xiàn)狀[J];中國材料進(jìn)展;2014年12期

4 劉本武;隋雪冰;邢雷;;某型燃?xì)廨啓C(jī)封嚴(yán)盤疲勞裂紋機(jī)理分析[J];航空發(fā)動機(jī);2014年01期

5 杜金輝;呂旭東;鄧群;莊景云;;GH4169合金研制進(jìn)展[J];中國材料進(jìn)展;2012年12期

6 王會陽;安云岐;李承宇;晁兵;倪雅;劉國彬;李萍;;鎳基高溫合金材料的研究進(jìn)展[J];材料導(dǎo)報;2011年S2期

7 王巖;邵文柱;甄良;;GH4169合金δ相的溶解行為及對變形機(jī)制的影響[J];中國有色金屬學(xué)報;2011年02期

8 謝錫善;董建新;付書紅;張麥倉;;γ″和γ′相強化的Ni-Fe基高溫合金GH4169的研究與發(fā)展[J];金屬學(xué)報;2010年11期

9 董星;張海錄;段雄;;水射流噴丸強化殘余應(yīng)力場的有限元模擬[J];機(jī)械工程學(xué)報;2010年18期

10 高玉魁;;噴丸強化對TC21高強度鈦合金疲勞性能的影響[J];金屬熱處理;2010年08期

相關(guān)博士學(xué)位論文 前1條

1 王巖;δ相對GH4169合金高溫變形及再結(jié)晶行為的影響[D];哈爾濱工業(yè)大學(xué);2008年

相關(guān)碩士學(xué)位論文 前10條

1 羅欽毫;TB6鈦合金表面納米化層的組織與性能研究[D];南昌航空大學(xué);2015年

2 曾旭;δ相對鎳基高溫合金GH4169低周疲勞行為的影響[D];華東理工大學(xué);2015年

3 李胡燕;GH4169鎳基高溫合金的組織和性能研究[D];東華大學(xué);2014年

4 田唐永;TC4鈦合金噴丸強化組織與性能研究[D];大連理工大學(xué);2012年

5 陳明;TC4鈦合金及其噴丸處理后的微動損傷特性[D];大連理工大學(xué);2012年

6 閆林林;超聲噴丸技術(shù)的理論與實驗研究[D];南京航空航天大學(xué);2010年

7 馮寶香;TC4-DT鈦合金噴丸強化研究[D];西安建筑科技大學(xué);2009年

8 馮帥;GH4169和1Cr17表面納米化后耐高溫氧化性的研究[D];大連交通大學(xué);2008年

9 劉海英;超聲噴丸強化機(jī)理的研究[D];太原理工大學(xué);2008年

10 張大;高壓水射流沖擊材料表面強化的研究[D];大連理工大學(xué);2006年

，

本文編號：2395440