共查询到19条相似文献,搜索用时 203 毫秒
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通过不同钝化半径的刀具对GH4169高温合金进行车削正交试验,结果表明:随着钝化半径的增加,表面残余应力先降低后增加;工件环向残余应力随着钝化半径的增加,工件内部残余压应力最大值增大,影响深度随之增加。由表面粗糙度和表面残余应力的敏感程度可知,进给量是影响表面完整性的最主要因素,其次是切削速度和切削深度。分析了不同钝化半径和切削参数对表面完整性特征的影响规律,建立了表面粗糙度表面残余应力的经验公式,得到了用于精加工GH4169高温合金较好的钝化半径范围0.02~0.03mm,以及较优的切削参数vc=60~70m/min,fn=0.05~0.075mm/r,ap=0.2~0.5mm。 相似文献
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PCBN刀具高速切削镍基高温合金GH4169的有限元模拟 总被引:1,自引:0,他引:1
《机械工程材料》2015,(7)
采用PCBN刀具对镍基高温合金GH4169进行了高速切削试验,通过正交试验分析了切削速度、切削深度、进给量对切削力的影响规律,在试验基础上利用多元线性回归分析基于最小二乘法建立了切削力的预测模型;基于Deform-3D软件建立了高速切削的有限元模型,对切削过程进行有限元模拟,得到了切削力、切削温度和应力场的分布;以切削力为指标对有限元模型进行了验证。结果表明:切削力随切削速度的增大而先增大后减小,随切削深度、进给量的增加而增大;回归分析显著性检验结果证明所建立的模型能对切削力进行有效预测,三向切削力模拟的综合平均偏差小于15%,验证了有限元模型的正确性和有效性。 相似文献
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利用材料试验机和SHPB装置对ZL109进行准静态和动态冲击压缩实验,确定了ZL109铝合金的本构模型参数。采用单因素试验法,模拟刀具前角、后角和刀尖圆弧半径对切削力和刀尖温度的影响。结果表明:刀尖圆弧半径对X和Y方向切削力影响最大,而前角对Z方向切削力影响最大,后角对刀尖温度的影响最大。通过正交试验法和极差分析可知,当刀具几何参数选择为前角γ0=0°,后角α0=7°,刀尖圆弧半径r=0.4mm时,PCD车刀切削ZL109铝合金时刀具的切削性能最优。 相似文献
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赵吉民 《机械设计与制造工程》2018,(8)
为探究刀具几何参数对钛合金的切屑形态和刀具磨损的影响,以TC11钛合金为研究对象,基于DEFORM-3D建立了三维切削有限元模型,并且对其进行了有限元分析。结果表明:相同的刀具前角的情况下,刀尖圆弧半径越大,切屑的卷曲程度越小;相同的刀尖圆弧半径下,刀具前角越大,切屑的卷曲程度越大。刀尖圆弧半径对切屑宽度的影响较小,但是对切屑的卷曲半径影响较大。三向切削力的幅值和刀具几何温度的分布范围与刀尖圆弧半径都呈现出正相关关系。随着刀具前脚和刀尖圆弧半径的增大,刀具的磨损深度不断增大,刀尖圆弧半径越大,增大的趋势越明显。 相似文献
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通过正交仿真试验分析300M钢在车削过程中切削速度V、背吃刀量a_p、进给量f以及刀尖圆弧半径r_ε对车削300M钢切削力的影响。采用方差分析法和极差分析法确定车削参数的最优组合,并检验4个因素对切削三向力的显著性。结果表明,4个因素中,背吃刀量a_p对切削力的影响最为显著,其次是进给量和刀尖圆弧半径,切削速度对切削力的影响程度最小。使用MATLAB软件对切削三向力与各个因素之间的关系进行多元线性回归分析,并建立切削三向力经验公式。通过对比分析经验公式与仿真分析得到的三向力,确定经验公式准确可靠。 相似文献
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Force modelling in shallow cuts with large negative rake angle and large nose radius tools—application to hard turning 总被引:1,自引:0,他引:1
Yong Huang Steven Y. Liang 《The International Journal of Advanced Manufacturing Technology》2003,22(9-10):626-632
In finish turning, the applied feedrate and depth of cut are generally very small. In some particular cases, such as the finishing of hardened steels, the feedrate and depth of cut are much smaller than tool nose radius. If a tool with a large tool nose radius and large negative rake angle is used in finish turning, the ploughing effect is pronounced and needs to be carefully addressed. Unfortunately, the ploughing effect has not yet been systematically considered in force modelling in shallow cuts with large negative rake angle and large nose radius tools in 3-D oblique cutting. In this study, in order to model the forces in such shallow cuts, first the chip formation forces are predicted by transforming the 3-D cutting geometry into an equivalent 2-D cutting geometry, then the ploughing effect mechanistic model is proposed to calculate the total 2-D cutting forces. Finally, the 3-D cutting forces are estimated by a geometric transformation. The proposed approach is verified in the turning of hardened 52100 steel, in which cutting conditions are typified as shallow cuts with negative rake angle and large nose radius tools. The workpiece material property of hardened 52100 steel is represented by the Johnson-Cook equation, which is determined from machining tests. The comparison between the experimental results and the model predictions is presented. 相似文献
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为了优化高温合金GH4169插铣加工过程中的切削参数,采用正交试验法进行高温合金GH4169的铣削试验。基于试验法建立了切削力与切削参数之间的经验公式,分析了各切削参数对切削力的影响规律。运用方差分析法检验了经验公式的显著性。结果表明:F_x、F_y、F_z都随着切削速度V_c、每齿进给量f_z、径向切深a_e的增大而增大;三个方向的切削力受径向切深a_e的影响最大,其次是切削速度V_c,每齿进给量f_z的影响最小,且Z方向切削力F_z大于X、Y方向切削力F_x、F_y。 相似文献
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为研究钛合金车削过程中鳞刺生成规律及有效抑制措施,分析了影响鳞刺生成的主要因素,采用弯矩法解析了鳞刺折断规律,进而建立了切削参数、刀具几何参数与刀尖弯矩的数学描述模型;通过MATLAB对模型进行求解,获知切削速度对刀尖弯矩的影响最小,而切削深度、进给量、刀尖圆弧以及刀具主偏角4个因素决定了刀尖弯矩的大小。为验证描述模型的正确性,进行了典型钛合金TC17外圆周断续切削实验,采集在恒定切削速度、不同切削深度、不同进给量、不同主偏角及不同刀尖圆弧条件下的鳞刺样本数据,并获得鳞刺折断规律曲线。实验结果表明:在小于临界切削深度和大于临界进给量条件下,实验结果与数学描述模型整体趋势一致,证明了数学描述模型的正确性。研究结果可为钛合金的高品质加工提供工艺技术及刀具优选方面的数据支撑。 相似文献
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Min Wang Binshi Xu Jiaying Zhang Shiyun Dong Shicheng Wei 《The International Journal of Advanced Manufacturing Technology》2013,67(5-8):1537-1548
Fe-based amorphous alloy, a new-type material, was developed as a special-purpose welt overlay for remanufacture. It was deposited on the worn-out part for resuming and upgrading part performance. The microstructure characteristics of the overlay was characterized, including microstructure, phase composition, thermostability, and microhardness. In order to get a comprehensive insight to the machining process of amorphous overlay, this paper presents an experimental investigation into the effect of various machining parameters and tool geometry (Edge) on the surface roughness, tool wear, chip morphology, and surface damage. Comparing larger rake angle of 15°and smaller nose radius of 0.4 mm with 5° and 0.8 mm at the same cutting parameters, we found that larger rake angle of 15° and smaller nose radius of 0.4 mm increased the R a surface roughness parameter. In the tests, crater wear was not observed, and the friction and wear on the minor cutting edge wear were heavy due to the spring back of the machined surface. In brief,abrasion, adhesion, fatigue, and chipping are the main wear mechanism. As the feed rate reduced and the depth of cut increased (from feed rate?=?0.06 mm/rev and depth of cut?=?0.3 mm to feed rate?=?0.09 mm/rev and depth of cut?=?0.2 mm), a number of physical changes occurred in the chip including reduced distance between serrations, increased shear band angle, and changed chip morphology from spiral to ribbon shape. The results show that strain and strain rate rises in the chips’ inside with the increase in cutting temperature. When the thermal softening exceeded strain hardening, the shear resistance decreased rapidly. Thus, the free surface of the chip presents the nodular and lamella structure. It was noted that specimens generated by larger rake angle of 15° and smaller nose radius of 0.4 mm showed poor surface roughness as well as extensive surface damage. 相似文献
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利用切削仿真软件Advant Edge对高速切削Ti6Al4V切削过程进行有限元模拟,研究了切削速度为200m/min、切削深度为0.085mm时刀具几何参数(前角γ_o、后角α_o、钝圆半径r_ε)对切削力的影响。通过分析计算求得切削力随刀具几何参数变化的一阶响应面数学模型,实现了利用刀具几何参数对切削力的预测,并通过误差计算和方差分析证明了预测模型的有效性。研究发现,在给定的参数变化范围内,刀具几何参数对_影响作用的大小顺序为前角γ_o钝圆半径r_ε后角α_o;对F_z影响作用的大小顺序为钝圆半径rε前角γ_o后角α_o。 相似文献
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通过预测加工304不锈钢时产生的切削力,从而对切削参数和刀具几何参数进行优化,是提高304不锈钢的加工精度、切屑控制及保障刀具寿命的基础。建立304不锈钢切削仿真模型,为提高模型的精确性,选择Johnson-Cook本构方程和黏结-滑移摩擦模型。结果表明:采用黏结-滑移摩擦模型的切削力预测结果更为准确,表明相对于纯剪切摩擦与库仑摩擦模型,黏结-滑移摩擦模型能更准确地描述刀-屑摩擦特性。展开不同参数下的切削力研究,研究发现:切削力随着刀具前角、后角和切削速度的增大而减小,随切削刃钝圆半径和切削厚度、宽度的增大而增大,其中切削宽度、厚度及前角对切削力大小影响较大。研究结果为304不锈钢切削效率的提高和切削机制的研究提供了理论依据。 相似文献