一种Al2O3基陶瓷刀具的切削性能研究

采用热压工艺制备了一种Al2O3／Ti（CN）陶瓷刀具材料,对其进行了切削性能试验,分析了其切削磨损机理并比较了三种陶瓷刀具的切削性能。试验结果表明,在切削淬硬45^#钢和铸铁时,Al2O3／Ti（CN）陶瓷刀具的耐磨性与Al2O3／TiC陶瓷刀具接近,但明显高于Al2O3／TiC／CaF2自润滑陶瓷刀具;Al2O3／Ti（CN）陶瓷刀具的后刀面磨损量随切削速度和背吃刀量的增加而增大。SEM分析发现,在切削淬硬45^#钢和铸铁时Al2O3／Ti（CN）陶瓷刀具后刀面主要磨损形式为磨粒磨损。     

车削0Cr18Ni9不锈耐热钢的刀具优选试验

分别采用YT15、YW2、YG6X硬质合金刀具和Fe-Al/Al2O3金属陶瓷刀具进行0Cr18Ni9不锈耐热钢的车削试验,进行刀具材料的优选。试验结果显示:切削速度较低时,YG6X和YW2刀具的耐用度和表面质量较好;切削速度较高时,Fe-Al/Al2O3陶瓷刀具的耐用度较好。     

Al2O3/TiC纳米复合刀具材料的力学性能与增韧强化机理

利用热压烧结工艺，制备成功Al2O3／TiC纳米复合陶瓷刀具材料。与同组分的微米级刀具材料相比，其断裂韧度和抗弯强度分别提高74．5％和23．5％。SEM观察表明，Al2O3／TiC纳米复合陶瓷刀具材料的断裂方式主要是穿晶断裂，材料的断口处存在大量的晶粒拔出。TEM观察到Al2O3／TiC纳米复合材料中有典型的内晶结构。     

Al2O3/TiC/CaF2自润滑陶瓷刀具切削过程中的减摩机理

在Al2O3/TiC陶瓷刀具基体内加入固体润滑剂CaF2来改善其摩擦学特性,制备出Al2O3/TiC/CaF2自润滑陶瓷刀具.以该陶瓷刀具对45钢进行干切削试验,结果表明添加固体润滑剂的Al2O3/TiC/CaF2自润滑刀具的摩擦因数比未添加固体润滑剂的Al2O3/TiC陶瓷刀具显著降低,表现出了良好的减摩效果.在切削过程中,Al2O3/TiC/CaF2自润滑陶瓷刀具中的固体润滑剂由于受到摩擦和挤压作用而析出,能在刀具前刀面上形成润滑膜,可阻止刀-屑间的粘着,显著降低前刀面与切屑间的平均摩擦因数.对自润滑陶瓷刀具切削后磨损表面显微分析表明,前刀面在切削过程中形成了自润滑膜的生成、破损、脱落和再生的循环过程.因此,Al2O3/TiC/CaF2自润滑陶瓷刀具在其整个生命周期内始终具有润滑效果.     

微织构(W,Mo)C基刀具和YG8刀具对钛合金干切削性能的影响

刀具切削钛合金时存在切削温度高、单位面积上切削力大等问题,微织构刀具可以有效减小摩擦力,减小切削力。通过正交实验法设计微织构参数,研究微织构参数对Al 2O 3/La 2O 3/(W,Mo)C无黏结相硬质合金刀具以及YG8刀具切削钛合金实验的切削性能影响。实验结果表明,合适参数的沟槽型微织构能有效降低Al 2O 3/La 2O 3/(W,Mo)C无黏结相硬质合金刀具和YG8刀具切削TC4钛合金的切削力,相同沟槽参数下,无黏结相硬质合金刀具的切削力明显低于YG8刀具的切削力;合适参数的沟槽型微织构能有效降低刀具刀屑界面的摩擦系数,相同沟槽参数下,无黏结相硬质合金刀具的摩擦系数大都低于YG8刀具的摩擦系数;沟槽深度10μm、沟槽间距100μm以及沟槽宽度30μm的沟槽参数下,切削钛合金时,无黏结相硬质合金刀具前刀面无明显磨损,后刀面只有边界磨损,YG8刀具发生崩刃,前刀面出现切屑的滞留。     

Al_2O_3-20%TiB_2/Al_2O_3-20%TiC对称型叠层陶瓷刀具的切削性能

以Al2O3为基体,以TiB2和TiC为增强相,通过粉末叠层以及热压烧结工艺制备了Al2O3-20%TiB2/Al2O3-20%TiC对称型叠层陶瓷刀具材料,对其抗弯强度与断裂韧度进行了测试,采用该材料刀具对淬火45钢进行高速切削试验,并与Al2O3-20%TiC陶瓷刀具的切削性能进行了对比。结果表明:对称型叠层陶瓷刀具材料的抗弯强度和断裂韧度分别为651 MPa和4.59 MPa·m1/2,比Al2O3-20%TiC陶瓷的分别提高了11 MPa和0.59 MPa·m1/2;对称型叠层陶瓷刀具的切削力和磨损均较小,切削性能明显优于Al2O3-20%TiC陶瓷刀具的。     

车削司太立合金时硬质合金刀具失效机理的试验研究

通过切削试验,研究了YG610和YS8两种硬质合金刀具车削难加工材料司太立合金的刀具失效机理。结果表明:YG610刀具的硬度和韧性都相对较好,刀具失效形式表现为磨损;YS8刀具硬度高,但韧性略有不足,刀具失效形式主要为破损。     

高温自润滑陶瓷刀具材料及其切削性能的研究

以TiB2为添加剂,Al2O3为基体,制备了Al2O3/TiB2陶瓷刀具材料。以该陶瓷刀具对淬硬钢进行高速干切削试验,利用其在切削高温作用下的摩擦化学反应,在刀具材料表面原位生成具有润滑作用的反应膜,从而实现Al2O3/TiB2陶瓷刀具材料本身的高温自润滑。研究了Al2O3/TiB2陶瓷刀具在切削高温作用下刀具表面的摩擦化学反应机理,分析了刀具表面自润滑膜的组成结构。结果表明：Al2O3/TiB2陶瓷刀具在干切削淬硬钢时,当切削速度大于120 m/min时,开始表现出高温自润滑性能。自润滑膜的组成为Al2O3/TiB2陶瓷刀具中TiB2的氧化产物,它能在刀具表面起到固体润滑剂的作用,进而降低前刀面的摩擦因数,减轻刀具的粘着磨损,提高刀具的耐磨性能,具有良好的减摩和抗磨作用。     

Al2O3/TiC梯度功能陶瓷刀具的切削性能及损坏机理

采用粉末叠层填充—轴向热压烧结工艺研制成功性能优良的Al2 O3/TiC梯度功能陶瓷刀具 ,并在柴油机排气阀外圆粗车工序中与普通陶瓷刀具LT55进行了对比切削试验。结果表明 ,Al2 O3/TiC梯度功能陶瓷刀具的寿命比LT55提高 50 %,梯度功能陶瓷刀具的破损主要是机械疲劳作用所致 ,而LT55刀具的破损主要是热疲劳作用的结果。     

加工含镍球墨铸铁时梯度陶瓷刀具的失效机理

研究了Al2O3／TiC梯度陶瓷刀具干切削含镍球墨铸铁的切削性能及损坏机理。结果表明,梯度陶瓷刀具的寿命约为硬质合金YS10刀具的1—2倍,且切削速度愈高,梯度陶瓷刀具的优越性愈显著;其损坏形式：低速切削时,为磨粒磨损;高速切削时,为剥落及粘结磨损。     

Wear properties of cemented carbides/Cu-based alloy composite strengthening materials for milling shoes

The microstructure and wear behavior of WC–8TiC–3TaC–8Co cemented carbide and CuZnNi alloy composite strengthening materials have been investigated by means of scanning electron microscopy (SEM), electron dispersion X-ray analysis (EDAX) and wear test. Effect of applied load and sliding distance on the wear behavior of the strengthening materials are also studied in this paper. The results show that the cemented carbide particles are surrounded by the α + β phases in the hardfacing layers. There exists an inter-diffusion zone at the interface of the cemented carbides and Cu-based matrix due to the mutual diffusion of elements. The wear volume of both the WC–8TiC–3TaC–8Co/CuZnNi and WC–8Co/CuZnNi composite strengthening layers increased with the increasing of applied load. The WC–8TiC–3TaC–8Co/CuZnNi hardfacing layers exhibited lower wear volume loss than that of WC–8Co/CuZnNi. According to the results of engineering application, the working efficiency and employing life of the milling shoes, which were strengthened by WC–8TiC–3TaC–8Co/CuZnNi composite materials, is by approximately two to three times the milling tools strengthened by WC–8Co/CuZnNi.     

Wear properties of cemented carbides/Cu-based alloy composite strengthening materials for milling shoes

The microstructure and wear behavior of WC–8TiC–3TaC–8Co cemented carbide and Cu–Zn–Ni alloy composite strengthening materials have been investigated by means of scanning electron microscopy (SEM), electron dispersion X-ray analysis (EDAX) and wear test. Effect of applied load and sliding distance on the wear behavior of the strengthening materials are also studied in this paper. The results show that the cemented carbide particles are surrounded by the α-Cu + β-Zn phases in the hardfacing layers. There exists an inter-diffusion zone at the interface of the cemented carbides and Cu-based matrix due to the mutual diffusion of elements. The wear volume of both the WC–8TiC–3TaC–8Co/CuZnNi and WC–8Co/CuZnNi composite strengthening layers increased with the increasing of applied load. The WC–8TiC–3TaC–8Co/CuZnNi hardfacing layers exhibited lower wear volume loss than that of WC–8Co/CuZnNi. According to the results of engineering application, the working efficiency and employing life of the milling shoes, which were strengthened by WC–8TiC–3TaC–8Co/CuZnNi composite materials, is by approximately two to three times the milling tools strengthened by WC–8Co/CuZnNi.     

陶瓷刀具材料切削加工G4335V高强钢时的耐磨性能研究

本文对Ａｌ２Ｏ３／ＴｉＣ陶瓷刀具材料切削加工Ｇ４３３５Ｖ高强钢时的切削性能和耐磨性进行了试验研究。结果表明：在低速切削条件下，Ａｌ２Ｏ３／ＴｉＣ陶瓷刀具和硬质合金刀具（ＹＴ１５）的抗后面磨损能力相差不大，而在高速切削条件下，前者的抗后面磨损能力远高于后者。Ａｌ２Ｏ３／ＴｉＣ陶瓷刀具前面的磨损形式主要为粘结磨损，后面的磨损形式主要为磨粒磨损。     

硬质合金刀具材料性能参数的灰色识别

采用灰色系统参数识别的方法，以材料的物理机械性能作为分析参数，对国产YT类和YG类硬质合金刀具材料与ISO标准牌号硬质合金之间的对应关系进行分析．结果与传统的依据材料成分的分类方法基本一致，为国际间参考使用硬质合金材料提供了理论依据。     

真空阴极电弧沉积（Ti,Al）N薄膜的应用研究

为了提高TiN涂层刀具的耐磨性,采用钛铝合金靶,以真空阴极电弧沉积法制备了（Ti,Al)N涂层,对膜层形貌成分,组织结构及硬度进行了测试及研究,并试验了（Ti,Al)N涂层高速钢钻头及YG6硬质合金刀具的使用寿命,结果表明：（Ti,Al)N涂层硬度高达HV0．1,15,3700,（Ti,Al)N涂层使高速钢钻头及YG6硬质合金刀具的使用寿命显著提高。     

WC-Ni3Al硬质合金切削奥氏体不锈钢的切削力及磨损研究

采用正交试验法对WC-Ni3Al硬质合金刀具切削奥氏体不锈钢过程中的切削力及磨损性能进行研究,并对切削深度、进给量以及切削速度对切削力的影响进行分析。利用指数回归分析建立主切削力的经验公式,结合切削用量显著性分析对主切削力进行了对比分析。试验表明:切削深度对切削力的影响最大;与WC-Co硬质合金相比,WC-Ni3Al硬质合金刀具的切削力以及后刀面磨损均优于WC-Co刀具。     

Resistance of a binderless cemented carbide to abrasion and particle erosion

A binderless cemented carbide has been evaluated in abrasion and erosion tests. The binderless carbide was compared with: SiC, Al₂O₃ and two conventional cemented carbides with 6% Co and different WC grain sizes (1 and 7 μm). In the abrasion tests, the materials were ground with silica, silicon carbide and diamond particles in the size range of 5–15 μm. The erosion tests were performed with 80, 200 and 600 μm silicon carbide erodents. The angle of impingement was 45° and the erodent velocity 70 m/s. In all tests, the conventional cemented carbides showed the highest, the binderless cemented carbide an intermediate and the ceramics the lowest wear resistance. Scanning electron and atomic force microscopy of the abraded surfaces revealed that the binderless cemented carbide was worn by a preferential removal of TiC grains. In erosion, the wear mechanism was largely plastic for the cemented carbides, whereas the ceramics were worn by micro-fracture. The SEM analysis also showed an impact scaling effect for the cemented carbides in erosion. This revised version was published online in August 2006 with corrections to the Cover Date.     

TiC-TiN-TiC-Al_2O_3涂层CP3型硬质合金抗弯强度及其分散性的研究

通过X衍射法对CP3型硬质合金涂覆TiC TiN TiC Al2 O3 四层硬质层的组织结构进行了研究 ,用扫描电镜观察了涂层的断口形貌 ,用划痕法测定了涂层与基体的结合力 ,用三点弯曲法测定了涂覆前、后该硬质合金的抗弯强度 ,并应用Weibull统计方法对该材料的抗弯强度及其分散性进行了分析。研究结果表明 :涂层组织由TiC、TiN和Al2 O3 组成 ,涂层中无发达的柱状晶 ,涂层与基体结合良好 ,涂覆后硬质合金的平均抗弯强度从涂覆前的2 119MPa下降到 15 80MPa ,但其抗弯强度的分散性变化不大     

热压条件下金刚石微粉的石墨化相变行为及对陶瓷断裂韧性的影响

研究了金刚石微粉在热压条件下的石墨化相变行为及对陶瓷材料断裂韧性的影响;初步认为在Al2O3/TiC陶瓷材料中适量添加金刚石微粉,能显著提高材料的断裂韧性,在该试验条件下,所添加的金刚石微粉已全部石墨化,由于热残余应力的作用,在氧化铝/石墨和碳化钛/石墨界面上有裂纹形成,但界面附近没有观察到明显的化学反应。