金刚石复合片刀具磨损机理研究

选用平均粒度10微米的金刚石复合片制成刀具,对高硅铝合金(Al-30wt%Si)进行切削实验。通过扫描电子显微镜分析了工件的形貌以及金刚石刀具前后刀面磨损的微观形貌。其磨损程度与切削路程为线性关系,金刚石刀具的磨损主要是后刀面机械摩擦磨损以及前刀面的粘接磨损,而没有出现像立方氮化硼刀具的化学磨损以及月牙洼磨损。     

SandvikCoromant公司推出对淬硬钢进行铣削时使用的合适嵌件

SandvikCoroman公司开发出一种对淬硬钢进行铣削时使用的GC1010嵌件，从而可提供一种高产的切削方案。由于GC1010的适用范围包括粗加工和精加工，因此该产品可被开发用于满足模具行业不断增长的需求。在对工具钢、ISO—H淬硬钢和ISOP钢材进行粗加工和精加工时，GC1010均能展现其优异性能。该嵌件还可提高ISO—K铸铁精加工工艺的生产效率。     

Sialon陶瓷刀具高速切削高温合金Inconel 718的切削性能和磨损机理的研究

本实验研究两种商业Sialon陶瓷刀片(牌号为KY1540、CC6060,分别是肯纳和山特维克公司生产)高速切削高温合金Inconel718的切削性能和磨损机理.采用XRD和SEM分析刀片的物相成分和显微结构,结果表明KY1540和CC6060主要的物相成分是α-和β-Sialon.通过测量切削长度和后刀面的磨损量,结果表明,在实验条件下由于CC6060具有较高的高温硬度,导致它的后刀面磨损量低于KY1540.两种刀片的磨损后刀面通过扫描电镜观察,发现两种刀片的磨损形式主要是沟槽磨损和后刀面磨损,磨损机理主要是磨粒磨损和粘结磨损.     

自润滑陶瓷刀具切削过程中的减摩机理研究

采用热压法CaF2作为添加剂,Al2O3/TiC(LT55)作为基体制备出了自润滑陶瓷刀具,并对其进行了干切削试验.在切削过程中,在刀具前刀面上能形成自润滑膜,从而使刀具具有减摩性能.用扫描电镜观察了前刀面和后刀面微观结构.LT55在切削加工45钢时,Al2O3/TiC/CaF2(ATF)自润滑陶瓷刀具前刀面的平均摩擦系数比未添加固体润滑剂的LT55陶瓷刀具显著降低,其主要原因是在ATF自润滑陶瓷刀具的前刀面上形成了一层固体润滑膜,这层润滑膜可起到减摩作用.自润滑刀具在切削过程中,自润滑膜经历生成、破损、脱落、再生成的循环过程,因此,ATF自润滑陶瓷刀具在其整个生命周期内都具有自润滑效果.自润滑刀具后刀面不存在固体润滑膜,具有较明显的磨料磨损特征.     

Al2O3／TiB2／SiCW陶瓷刀具加工镍基合金时的磨损机理研究

研究了Ａｌ２Ｏ３／ＴｉＢ２／ＳｉＣＷ陶瓷刀具加工Ｉｎｃｏｎｅｌ７１８镍基合金时的切削性能和磨损机理。结果表明；在低速切削条件下，Ａｌ２Ｏ３／ＴｉＢ２／ＳｉＣＷ和硬质合金刀具的抗后刀面磨损的能力相差不大；而在高速切削条件下，前者的抗后刀面磨能力远高于后者。     

Si3N4陶瓷刀具在切削淬硬钢时的磨损行为

采用两种Ｓｉ２Ｎ４刀具在普通车床上对ＣｒＷＭｎ和４５钢进行切削试验，并用ＳＥＭ，ＥＤＡＸ，ＸＰＳ等方法对刀具的磨损进行分析。结果指出：试验的陶瓷刀具材料在切削不同淬硬钢时均存在最佳切削速度。在ＦＤ０１相比，ＦＤ０２陶瓷刀具有更佳的切削性能，最佳切削速度可提高７８％。在最佳速度以下切削，刀具侧面将发生粘着磨损；在最佳速度以上，则被加工材料产生微区熔化，导致材料大面积转移，发生剥层磨损，最佳速度以下切     

梯度硬质合金金刚石涂层刀具的切削性能研究

梯度硬质合金是金刚石涂层产品新的基体材料.现场切削实验可有效、直观地评价金刚石涂层刀具的性能。采用梯度硬质合金金刚石涂层可转位刀片车削硅铝合金,研究切削参数对加工面质量及刀具磨损的影响。结果表明,梯度硬质合金金刚石涂层刀具加工的工件面粗糙度低、光泽度好且不黏刀。切削20min后,加工面粗糙度最佳值为1.57μm,刀具后刀面磨损为0.1mm,远小于失效判据VB=0.30mm,是很好的金刚石涂层产品基体材料。     

复合合金化对奥氏体中锰钢切削加工性的影响及切削加工性的模糊综合评判

在传统奥氏体中锰钢中添加不同含量的合金元素Mo, Cr, Nb和RE进行复合合金化处理,测试了其导热性及切削加工性,研究了复合合金化对奥氏体中锰钢切削加工性的影响,建立了二级模糊综合评判模型,以奥氏体锰钢的硬度、抗拉强度、延伸率、冲击韧性和热导率作为影响因素,对切削加工性进行定量分析. 结果表明,复合合金化处理可一定程度上改善奥氏体锰钢的切削加工性,合金元素Mo, Cr和Nb含量分别为1.87wt%, 2.43wt%和0.059wt%时试样的刀具后刀面平均磨损宽度VB值比未经合金化处理的ZGMn13钢减少了14.3%. 用二级模糊综合评判模型对奥氏体锰钢的切削加工性进行评价,通过本模型获得的评价指标与刀具磨损实验获得的VB值相关性显著,相关系数为–0.87334,存在高度的线性负相关,评判结果与VB值基本一致,评判模型符合生产实际,结果准确有效.     

PDC刀具切削硅铝合金的有限元模拟分析

根据主要部分工件材料测试数据,通过ansys／ls-dyna对PDC切削硅铝合金的模拟,采用自适应网格划分分离切屑,实际切削实验数据表明结果可靠。从工件受力和变形以及能量等的角度进行综合分析,硅铝合金在后刀面受压同时受到强烈的剪切作用,提出了改变刀尖角度和改变刀具受力布局使刀具磨损合理、提高工件表面质量的思路。     

全球切削刀具新材料和涂层技术现状

近代金属切削刀具材料从碳素工具钢、高速钢发展到今日的硬质合金、涂层硬质合金、陶瓷、立方氮化硼等超硬刀具材料,使切削速度从每分钟几米飚升到千米乃至万米。随着数控机床和难加工材料的不断发展,刀具实有难以招架之势。要实现高速切削、干切削、硬切削必须有好的刀具材料。在影响金属切削发展的诸多因素中,刀具材料起着决定性作用。     

Tool life and wear of WC–TiC–Co ultrafine cemented carbide during dry cutting of AISI H13 steel

WC–5TiC–10Co ultrafine cemented carbides were prepared and used for the cutting tool for AISI H13 hardened steel. The effect of cutting parameters on the tool life and tool wear mechanism was investigated, and conventional cemented carbide with the same composition and medium grain size were prepared for comparison. The results showed that WC–5TiC–10Co ultrafine cemented carbides possess higher hardness and transverse rupture strength, and showed better cutting performance than conventional insert with the same cutting condition. Tool life was analyzed by an extended Taylor's tool life equation, indicating that cutting speed played a profound effect on the tool life and wear behavior of both cutting inserts. SEM and EDS analysis revealed that there were major adhesive wear and minor abrasive wear on the rake of WC–5TiC–10Co ultrafine inserts, and increase of cutting speed resulted in a transition from abrasion predominant wear mechanism to adhesive wear on the flank face. As for the conventional inserts, there were combination of more serious abrasive and adhesive wear on the rake and flank. The favorable cutting performance of ultrafine WC–5TiC–10Co inserts was attributed to the higher hardness and less thermal softening during machining.     

新型陶瓷刀具的切削性能研究

本文研究了山东工业大学机械工程学院研制的新型陶瓷刀具材料（包括ＪＸ－２，Ｈ５，Ｈ１３和Ｈ２１等）分别切削铸铁（ＨＴ２０）淬火４５号钢和难加工材料ＧＨ９９时的切削性能，探讨了各陶瓷刀具的抗磨损能力，实验研究了切削速度和进给量对刀具磨损的影响，并对切削条件进行了优化。     

硬质合金粉末表面涂层陶瓷的材料

利用溶胶－凝胶法在ＴｉＣ粉末,（Ｗ,Ｔｉ）粉末表面涂层Ａｌ２Ｏ３陶瓷,通过热压烧结制得了两种新型涂层的刀具材料（ＦＴＣ１和ＦＴＣ２）,粉末涂层材料ＦＴＣ１和ＦＴＣ２的力学性能满足刀具材料的使用要求。利用扫描电镜观察发现基体粉末表面较均匀地涂覆了一层α－Ａｌ２Ｏ３陶瓷,并对材料的力学性能和微观结构进行了分析。     

Finite element simulation and experimental analysis of B4C-TiB2-SiC ceramic cutting tools

Here, cutting properties and wear mechanism of the home-made B₄C-TiB₂-SiC ceramic cutting tools in turning of AISI 4340 steel workpieces were studied through a combination of finite element simulation using Deform-3D software and turning experiments. Simulation results show that cutting parameters have significant effects on the main cutting force and tool temperature of the B₄C-TiB₂-SiC cutting tool. The optimal cutting parameters for the ceramic cutting tool are cutting speed of 300 m/min, depth of cut of .3 mm, and feed rate of .1 mm/r. Experimental results show the cutting length of the B₄C-TiB₂-SiC cutting tool is about 101 m, which is 21.0% and 32.9% larger than that of the home-made B₄C-TiB₂ ceramic cutting tool and commercially available tungsten carbide tool, indicating that the B₄C-TiB₂-SiC cutting tool has a desired service life. The surface roughness of the workpieces processed by the B₄C-TiB₂-SiC cutting tool is 2.43 µm, which is 29.4% lower than that of the workpieces processed by the B₄C-TiB₂ cutting tool, indicating that the B₄C-TiB₂-SiC cutting tool has a satisfying machining accuracy. Wear forms of the B₄C-TiB₂-SiC ceramic cutting tool involve craters, chipping, and flank wear, and the main wear mechanisms are abrasive, adhesive, oxidative, and diffusion wear.     

Performance and wear mechanism of spark plasma sintered WC-Based ultrafine cemented carbides tools in dry turning of Ti–6Al–4V

Cutting performance and failure mechanisms of spark plasma sintered (SPS) ultrafine cemented carbides in dry turning Ti–6Al–4V were studied. The tools of UYG8 (WC-8wt%Co) and UYG8V2B10 (WC-8wt%Co-0.2 wt%VC-1.0 wt%cBN) exhibited higher lifetime and better processing quality than the commercial YG8 cemented carbide tool. The cutting distance of UYG-8 and UYG8V2B10 tools are 1.8 and 1.6 times longer than that of YG8, respectively. Cutting-edge breakage was found as the main failure forms of the SPS cemented carbide tools containing low Co content (≤6 wt%), whereas the SPS cemented carbide tools containing high Co content (≥8 wt%) exhibited flank and rake wear as main failure forms caused by abrasion, adhesion, diffusion, and oxidation. UYG8V2B10 tool wear mechanism was affected by cutting speed and depth. Wear mechanisms of UYG8V2B10 tool are mainly adhesive wear and oxidative wear at low cutting speed, but follow adhesive wear and diffusive wear at higher cutting speed. Moreover, with increasing cutting depth, tool failure forms are mainly breakage and chipping, largely induced by high cutting temperature and severe cutting vibration.     

Tool wear characteristics analysis of cBN cutting tools in high-speed turning of Inconel 718

Nickel-based superalloy is a critical material for turbine engine components in the aerospace application, but the poor machinability and low machining efficiency have further hampered it to be used widely. Cubic boron nitride (cBN), having extreme hardness and chemical inertness, is the potential candidate to process superalloys. In this paper, we systematically investigated the tool wear characteristic of cBN at different cutting speeds in dry turning of Inconel 718 by experiments and FEM simulations. The FEM model with initial flank wear land (VB) was established and validated. Effects of cutting speeds (200–400 m/min) on cBN tool life and wear mechanisms were systematically investigated. Effects of tool flank wear on cBN tool cutting edge temperature field and Inconel 718 machined surface layer stress distribution were analyzed by FEM simulations.     

Improvement of cutting performance of SiAlON ceramic by texture engineering in turning superalloys

High speed and high efficiency machining of superalloy is a big technological challenge faced by the cutting tool industry in the world. In the present study, cutting performance of nickel-based superalloy was significantly improved by engineering the texture of SiAlON ceramic cutting tools with grains oriented parallel to the cutting edge. Orientation of the rod-like grains played a significant role in the wear resistance of SiAlON ceramic. With the rod-like grains parallel to the cutting edge of the tool, the resistance to notched wear and peeling was much higher, resulting in slow and stable flank and rake wear. The tool life of the textured tool with rod-like grains parallel to the cutting edge was 17% higher than that of the untextured tool. On the other hand, for the tools with the grains perpendicular to the rake or flank face, the friction generated during machining would be parallel to the grain direction, which led to the rapid peeling on the tool surface along the moving direction of the workpiece or the chip flow direction, resulting in rapid tool wear. The preferred orientation of mechanical properties designed by engineering grain orientation provides the possibility to optimize the cutting performance of SiAlON ceramic tool in turning superalloys.     

Reliability prediction of a microwave sintered Si3N4-based composite ceramic tool

The wear life reliability prediction model of microwave sintered Si₃N₄/(W,Ti)C/Y₂O₃/MgO/Al₂O₃ composite ceramic tools based on the random distribution characteristics of hardness and fracture toughness of ceramic tool material was established. It showed that the Vickers hardness of ceramic tool materials followed a normal distribution and the fracture toughness followed a lognormal distribution. Distribution law of wear life can be determined by the joint distribution of hardness and fracture toughness. Experimental research on tool reliability of continuous dry cutting quenched high quality carbon steel T10A was carried out and the applicability of the tool reliability prediction model was verified. The results showed that the error between the theoretical reliable life and the actual life of the ceramic tool was less than 5% under the same reliability when the reliability was above 0.5.     

Experimental investigation of different morphology textured ceramic tools by in-situ formed for the dry cutting

Surface texture is considered an important measure to improve the cutting performance of a tool. In this study, we have prepared three types of textured and conventional tools on the rake face by an in-situ formed method. During the experiment, the best parameters of three types of textured tools were selected for dry cutting AISI 1045 steel at different cutting speeds. Cutting forces, cutting temperatures, workpiece surface roughness, and tool wear were measured during the cutting process. The results showed that textured tools have significantly reduced cutting force, cutting temperature, and tool wear, and the roughness of the workpiece was improved compared with the conventional tool. The micro-pit texture tool has less stress contact region than the micro-groove width texture tool, but the micro-groove width texture tool exhibiting the best cutting performance. This investigation clearly showed that the textured tool prepared by the in-situ formed method has improved cutting performance.