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TC17钛合金铣削刀具磨损对残余应力影响研究 总被引:2,自引:0,他引:2
为了获得高性能航空发动机用TC17钛合金材料铣削过程中刀具磨损对残余应力的影响规律,通过对不同刀具后刀面磨损量下铣削工件表层残余应力的测试,建立了刀具磨损对残余应力的影响关系,并对影响机理进行了分析。结果表明,硬质合金刀具低速铣削钛合金时,刀具对已加工表面的挤光效应引起的残余压应力占主导地位;不同刀具后刀面磨损量下,残余压应力沿深度方向先增大达到一个最大压应力值后,然后减小趋向于零应力;表面残余应力、最大残余压应力以及残余应力的影响深度都随刀具后刀面磨损量的增大呈增大趋势。 相似文献
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碳化硅铝基复合材料具有优良的导热性、较高的比强度和比刚度,在航空航天领域具有广泛的应用前景。由于此复合材料中含有增强相,导致材料的切削加工性能变差。通过试验分析了不同颗粒体积分数(纳米级5%、微米级25%)SiCp/Al复合材料和切削参数(切削速度、背吃刀量、进给量)对刀具磨损和工件表面质量的影响,并对刀具磨损机理进行了研究。试验结果表明,车削微米级25%SiCp/Al材料时聚晶金刚石PCD(Polycrystalline Diamond)刀具磨损更严重,且工件表面质量更差。随着进给量和背吃刀量的增大,工件表面粗糙度值增大,刀片前刀面磨损严重;随着切削速度的增大,工件表面粗糙度值减小,刀片前刀面磨损量增大。选取本文切削参数进行SiCp/Al复合材料的切削加工时,发现刀具磨粒磨损、微崩刃是PCD刀具后刀面磨损的主要成因,且刀具前刀面也会产生积屑瘤。研究结果可为SiCp/Al复合材料PCD车削工艺的优化提供理论基础。 相似文献
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为探索碳纤维增强树脂基复合材料(CFRP)铣削加工过程中切削力与工艺参数之间的映射关系,建立CFRP铣削加工有限元仿真模型并对切削力进行分析。基于ABAQUS软件通过定义材料属性、材料失效模型、纤维铺层数和纤维方向建立了CFRP铣削加工二维有限元仿真模型,并对该模型进行了实验验证。基于该模型,分析了切削力与纤维方向角、铣削速度、每齿进给量和刀具前角等工艺参数之间的映射关系。仿真结果表明:纤维方向角从0°增大到90°,切削力呈现降低趋势,而纤维方向角从90°增大到180°,切削力呈现增大趋势。随着切削速度和每齿进给量的增大,切削力随之增大,而随着刀具前角增大,切削力随之减小。 相似文献
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钛合金TB6铣削表面粗糙度对其使用性能具有重要影响,通过试验研究端面铣削参数、干铣削和刀具磨损对表面粗糙度及表面缺陷的影响。研究表明:表面粗糙度对每齿进给量变化最为敏感,其次是铣削宽度,再次为铣削深度,铣削速度最小;刀具磨损量(VB)对粗糙度产生明显影响,尤其VB大于0.2mm时,表面粗糙度将急剧增加,并导致划痕、孔洞缺陷;不同铣削条件下均存刀痕、侧流、隆起等缺陷;干铣削时加工表面出现熔敷物或熔滴,并增大毛刺;毛刺随切削速度的增大而变小,随刀具磨损量VB的增加而变大。钛合金TB6适宜在冷却润滑条件下低速铣削加工。 相似文献
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为了研究TC11钛合金铣削加工过程中刀具磨损对加工表面质量的影响规律,设计了刀具磨损与铣削表面粗糙度、表面残余应力的试验。结果表明:TC11钛合金铣削加工过程中的刀具磨损可以分为:初期磨损、正常磨损、剧烈磨损三个阶段。当刀具处于"初期磨损"时,TC11铣削表面粗糙度随切削时间逐渐减小,铣削表面残余应力也呈减小趋势;当刀具处于"正常磨损"阶段时,铣削表面粗糙度和铣削表面残余应力都呈增加趋势,但增加的速度平稳;当刀具进入"剧烈磨损"阶段时,铣削表面粗糙度迅速增大,表面残余应力也较前两个阶段显著增加。另外,试验过程中的TC11铣削表面残余应力均表现为压应力。 相似文献
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钛合金薄壁件铣削过程中,刀具角度对铣削过程中的工件变形、铣削力、铣削振动等影响显著。为减轻刀具磨损延长刀具寿命,通过ABAQUS软件建立钛合金Ti6Al4V薄壁件铣削过程仿真模型,以铣削力和铣削温度为评价指标,采用单因素和正交法分析了刀具前角、后角及螺旋角对铣削力和铣削温度的影响规律,并对铣削力仿真结果进行试验验证。仿真结果表明:前角增大,铣削力减小,铣削温度呈波动趋势变化;后角增大,铣削力减小,铣削温度先减小后增大;螺旋角增大,最大轴向力增大,最大切向力缓慢减小,最大径向力基本不变,铣削温度先减小后增大。通过正交试验和极差分析,明确不同因素对指标影响程度的主次顺序和因素的最优水平组合。 相似文献
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针对GH4169难加工材料,采用单因素实验法,研究了不同切削参数下刀具钝化对面粗糙度的影响,实验表明:使用钝化刀具加工形成的表面粗糙度较未钝化刀具有所下降,表面质量得以提高;切削深度由刃口半径的0.5倍变化到4倍时,表面粗糙度呈先减小后增大趋势,当切削深度是刃口半径的2倍时表面粗糙度最低. 相似文献
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本文以Al-50wt%Si高硅铝合金为研究对象,采用单因素试验方法进行无涂层硬质合金刀具干式铣削试验,分析切削参数对刀具磨损和表面粗糙度的影响。结果表明:表面粗糙度受每齿进给量的影响最显著,随每齿进给量的增加而增加,当每齿进给量从0.07 mm/z增加到0.16 mm/z时,表面粗糙度增加2倍;刀具磨损受切削速度的影响最显著,随切削速度的增加而增加,当切削速度从140 m/min增加到260 m/min时,切削总长度降低3倍,而刀具后刀面磨损量仅是260 m/min速度下的0.8倍;表面粗糙度随刀具磨损的增加呈现先增加后降低的变化趋势,切削长度从350 mm增加到1 750 mm,刀具磨损量平均增加4.5倍,而表面粗糙度却下降2倍;硬质合金刀具主要的磨损形式为磨粒磨损、崩刃。 相似文献
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超高强度钢立铣工件温度分析及对加工表面质量的影响 总被引:1,自引:0,他引:1
以航空难加工材料300M钢为研究对象,基于立铣加工中的工件温度判断在铣削加工中是否出现了金相组织转变,进而分析不同工况下影响加工表面质量的因素。首先,将移动热源法应用于铣削加工中,计算考虑后刀面磨损的立铣加工工件温度,实验表明,计算值与实验值相比误差在10%以内。然后,分析了工件温度在时间上与空间上的分布,以及不同刀具磨损和加工参数条件下工件表面的温升规律,据此预测加工表面是否出现了组织转变,并结合金相组织观察进一步确认。最后,依据加工表面质量物理层面残余应力和显微硬度的检测数据,初步探讨了各因素对表面质量的影响。结果表明,在研究的加工参数范围内,并未达到金相组织转变温度,表面质量主要受铣削热力作用下的剪切面塑性凸出效应、后刀面挤光效应和热效应的影响。 相似文献
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《中国航空学报》2021,34(4):465-475
Severe tool wear and poor surface quality are the main problems during micro machining of cemented carbide. In this work, an innovative hybrid process of laser-induced oxidation assisted micro milling (LOMM) was proposed to solve the problems. A nanosecond laser was utilized to induce oxidation of the WC-20%Co material, producing loose oxide which was easy to remove. The micro machinability of the material was improved by laser-induced oxidation. The oxidation mechanisms of cemented carbide were studied. A microgroove with a depth of 2.5 mm and aspect ratio of 5 was fabricated successfully. The milling force, surface quality and tool wear mechanisms were investigated. For comparison, a microgroove was also fabricated with conventional micro milling (COMM) using identical milling parameters. Results revealed that in LOMM the milling force and tool wear rate were extremely low during removing the oxide. The machined surface quality and dimensional accuracy achieved by LOMM were superior to those obtained by COMM. The surface roughness Sa of the microgroove bottom reached 88 nm in LOMM, while the cross-sectional geometry of the microgroove was a trapezoid. Perpendicularity of the microgroove sidewall machined by LOMM was better than that by COMM. The tool wear forms in LOMM were coating spalling and slight tool nose breakage. Compared with COMM, the tool life in LOMM was prolonged significantly. It indicates that the proposed hybrid process is an effective and efficient way to fabricate high aspect ratio micro-features with high dimensional accuracy. 相似文献
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《中国航空学报》2023,36(6):402-419
Large-size thin-walled curved surface parts of pure iron are crucial in aerospace, national defense, energy and precision physical experiments. However, the high machining accuracy and surface quality are difficult to achieve due to the serious tool wear and deformation when machining the parts with conventional cutting tools. In this paper, an elliptical vibration cutting (EVC) with active cutting edge shift (ACES) based on a long arbor vibration device is proposed for ultra-precision machining the pure iron parts by using diamond tool. Compared with cutting at a fixed cutting edge, the influence of ACES on the EVC was analyzed. Experiments in EVC of pure iron with ACES were conducted. The evolutions of the surface roughness, surface topography, and chip morphology with tool wear in EVC with ACES are revealed. The reasonable parameters of ultra-precision machining the pure iron parts by EVC with ACES were determined. It shows that the ACES has a slight influence on the machined surface roughness and surface topography. The diamond tool life can be significantly prolonged in EVC of pure iron with ACES than that with a fixed cutting edge, so that high profile accuracy and surface quality could be obtained even at higher nominal cutting speed. A typical thin-walled curved surface pure iron part with diameter ∅240 mm, height 122 mm, and wall thickness 2 mm was fabricated by the presented method, and its profile error and surface roughness achieved PV 2.2 μm and Ra less than 50 nm, respectively. 相似文献