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SiC颗粒具有较高的硬度,使Al/SiCp复合材料在切削时刀具磨损剧烈。纳米硬质合金具有较高的硬度、韧性及良好的抗磨损能力。制备了纳米硬质合金刀具WC-7Co,对Al/SiCp复合材料进行了切削实验,研究了纳米硬质合金刀具磨损机理和Al/SiCp复合材料的切屑去除机理,以及刀尖处后刀面磨损值。研究认为,纳米硬质合金刀具磨损的机理为SiC颗粒的微切削作用引起的磨料磨损,及SiC颗粒对刀尖刃口的高频、断续冲击引起的微崩刃及微破损,Al/SiCp复合材料的切削实质是断续切削;Al/SiCp复合材料去除机理为切屑的崩碎去除;纳米硬质合金后刀面磨损值较普通硬质合金小30%~50%。 相似文献
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针对SiC颗粒硬度高,切削Al/SiCp复合材料时刀具磨损剧烈,本文提出用具有较高硬度、韧性及良好抗磨损能力的WC-7Co制备纳米硬质合金刀具,并对Al/SiCp复合材料进行了切削实验。研究了纳米硬质合金刀具磨损机理和Al/SiCp复合材料的切屑去除机理,以及刀尖处后刀面磨损值。研究认为,纳米硬质合金刀具磨损的机理为SiC颗粒的微切削作用引起的磨料磨损,及SiC颗粒对刀尖刃口的高频、断续冲击引起的微崩刃及微破损;Al/SiCp复合材料的切削实质是断续切削;去除机理为切屑的崩碎去除;纳米硬质合金后刀面磨损值较普通硬质合金小30%~50%。实验表明,纳米硬质合金较普通硬质合金更适于加工Al/SiCp复合材料。 相似文献
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《机械制造与自动化》2017,(1)
分析了SiCp/Al复合材料在铣磨过程中的加工特性,在现有的研究基础上建立了一个针对SiCp/Al复合材料的铣磨力模型,并对铣磨力进行了预测与验证,证明了该模型的有效性。通过模型和试验结果得出,选择合理的切削用量可以有效地降低铣磨力,提高零件的加工质量。 相似文献
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SiCp/Al复合材料动态去除过程中极易发生颗粒损伤,为避免或利用复合材料切削加工过程中的颗粒损伤现象,优化SiCp/Al复合材料切削加工,深入研究了SiCp/Al复合材料切削的颗粒损伤现象及其对切削加工的影响。首先,通过位错塞积理论和切屑根部微观观察,揭示了SiCp/Al复合材料切削的颗粒损伤机理,发现位错塞积引起的应力集中是导致界面脱粘的主因,颗粒断裂主要是由集中应力、刀刃挤压颗粒、局部颗粒聚集挤压以及颗粒连成网状结构引起;然后,基于考虑颗粒影响的动态本构模型、Eshelby等效夹杂理论、Weibull统计分布和刀刃-颗粒接触分析,建立了SiCp/Al复合材料切削的颗粒损伤度模型,并借助图像处理技术验证了模型的有效性;最后,根据颗粒损伤度预测结果,分析了颗粒损伤度对SiCp/Al复合材料切削加工的影响。结果显示,颗粒损伤度增大,会使切屑锯齿化程度增强,并严重降低已加工表面质量;颗粒损伤会显著影响颗粒强化效应,导致切削力随颗粒含量增大先升后降、随颗粒尺寸增大而降低。 相似文献
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试验研究了普通和超声切削新型颗粒增强金属基复合材料SiCp/Al的切削特性 ,得到超声振动切削该材料的切屑形态、切削力变化规律 相似文献
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以亚微米级(130nm)SiCp和(100~200)目(149~75μm)Al粉为原料,采用冷压烧结和热挤压方法制备出不同体积含量的微米SiCp增强Al基复合材料,研究了其分形特性和耐磨性能.结果表明:SiCp/Al基复合材料具有分形特性,SiCp/Al基复合材料耐磨性优于市售挤压态锡青铜QSn6.5-0.4和纯Al,且随SiCp含量增加,复合材料的分形维数增大,耐磨性能提高;磨损表面形成Al基体+孔隙+弥散分布SiCp的理想耐磨组织. 相似文献
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高速正交切削SiCp/Al复合材料切削温度仿真研究 总被引:1,自引:0,他引:1
使用ABAQUS有限元软件对高体分SiCp/Al复合材料的颗粒和基体进行分别定义,仿真研究了高速切削复合材料时的温度场,分析了切削过程中切削用量和刀具角度对工件切削温度的影响。结果表明:在切削过程中,与刀具接触位置的颗粒温度较高且应力值较高;SiC颗粒的温度较Al基体的温度低;第一变形区发现一条沿着剪切角方向非常明显的温升带。在稳定切削阶段,与刀尖接触位置的工件温度较高,且应力集中现象总是发生在SiC颗粒上。随着切削深度和切削深度的增加,切削过程中工件的最高温度均随之增加;随着刀具前角和后角的增大,切削过程中工件的最高温度均随之降低。 相似文献
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0 INTRODUCTIONAs we know, metal matrix comPOsites (MMCs)are one kinds of advanced materials. Comparing withmetal materials, they show higher specific properties.Because MMCs have a 1ot of special properties, theyare more idea1 structure materials for aviation, spacenavigation industry and automobile industry.Theywill be used widely in the soon future.Aluminum-matrix comPOsites have attracted considerable acade-mic and industrial attention.With aluminum matrixcomposites reinforced wit… 相似文献
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Xun Li Fan Bai Yu Fu 《The International Journal of Advanced Manufacturing Technology》2017,91(9-12):3007-3014
With the volume fraction of SiC increasing, the machinability and electrical machining performance of SiCp/Al metal matrix composites (SiCp/Al MMCs) decreases gradually. Therefore, it is difficult to machine small holes in high volume fraction SiCp/Al MMCs. Based on the material properties and grinding mechanism, the small hole helical mill-grinding process in high volume fraction SiCp/Al MMCs with super abrasive wheel is presented. Furthermore, the wheel kinematic characteristic is analyzed during hole helical mill-grinding. The essential reason for reducing the hole exit defects is presented, which is changing the main feeding direction from axial to tangential. Meanwhile, the experiments of small hole helical mill-grinding in 65% volume fraction SiCp/Al MMCs are carried out. The experimental results show this process has the superiority in decreasing axial force, avoiding hole exit defects, and improving the small hole machinability. Under the premise of no obvious defects in the orifice and the inner surface roughness no more than Ra0.4 μm, the wheel grits and parameters in rough and finish machining are optimized to increase the hole machining efficiency and wheel life. At last, the experimental results fully illustrate that the small hole helical mill-grinding in high volume fraction SiCp/Al MMCs with high efficiency and quality has great superiority and application value. 相似文献
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SiCp尺寸及含量对Al基复合材料磨损表层、亚表层形貌的影响 总被引:3,自引:0,他引:3
分别以亚微米级 (130nm)、微米级 (14 μm)SiCp和微米级 (2 0 0目 )Al粉为原料 ,采用冷压烧结和热挤压方法制备出不同体积含量 (1 5 %、 5 % )亚微米、微米级SiCp增强Al基复合材料。研究复合材料磨损表面、亚表层形貌 ,结果表明 :SiCp/Al复合材料具有优良的耐磨性能 ,随着SiCp尺寸的增大 ,含量的增高 ,耐磨性能提高 ;其耐磨机理是磨损表面和亚表层在摩擦推挤形变的作用下形成了Al基体加尺寸适中、近球状、分布弥散SiCp的耐磨组织 相似文献
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Rajesh Kumar Bhushan Sudhir Kumar S. Das 《The International Journal of Advanced Manufacturing Technology》2013,65(5-8):611-624
7075 aluminum (Al) alloy as matrix and silicon carbide (SiC) as reinforcement has been identified since it has potential applications in aircraft and space industries because of lower weight to strength ratio, high wear resistance and creep resistance. Thorough investigations about the microstructure and characterization of Al alloy/SiC composite are needed so that metal matrix composites (MMCs) fabricated for aircraft and space industries are defect free and have sound microstructure. Objective of this research work are the fabrication and microstructural investigations of AA7075–SiCp MMCs. 7075 Al alloy is reinforced with 10 and 15 wt.% SiCp of size 20–40 μm by stir casting process. The resulting as-cast composite structures are analyzed using scanning electron microscopy, X-ray diffraction (XRD), differential thermal analysis, and electron probe microscopic analysis (EPMA). SiCp distribution and interaction with 7075 Al alloy matrix is studied. The 7075 Al alloy–SiCp composite microstructure showed excellent SiCp distribution into 7075 Al alloy matrix. In addition to this, no evidence of secondary chemical reactions is observed in XRD and EPMA analysis. Decomposition step in derivative thermogravimetric curve is seen at temperature of 1,257, 1,210, and 1,256 °C for 7075 Al alloy, AA7075/10 wt.%/SiCp (20–40 μm) and AA7075/15 wt.%/SiCp (20–40 μm) composites, respectively. So, these composites can be successfully used for applications where temperature does not exceed beyond 1,250 °C. 相似文献
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The existing research on SiCp/Al composite machining mainly focuses on the machining parameters or surface morphology.However,the surface quality of SiCp/Al composites with a high volume fraction has not been extensively studied.In this study,32 SiCp/Al specimens with a high volume fraction were prepared and their machining parame-ters measured.The surface quality of the specimens was then tested and the effect of the grinding parameters on the surface quality was analyzed.The grinding quality of the composite specimens was comprehensively analyzed taking the grinding force,friction coefficient,and roughness parameters as the evaluation standards.The best grinding parameters were obtained by analyzing the surface morphology.The results show that,a higher spindle speed should be chosen to obtain a better surface quality.The final surface quality is related to the friction coefficient,surface roughness,and fragmentation degree as well as the quantity and distribution of the defects.Lower feeding amount,lower grinding depth and appropriately higher spindle speed should be chosen to obtain better surface quality.Lower feeding amount,higher grinding depth and spindle speed should be chosen to balance grind efficiently and surface quality.This study proposes a systematic evaluation method,which can be used to guide the machining of SiCp/Al composites with a high volume fraction. 相似文献