卧式砂磨机结构优化研究

对卧式砂磨机进行设计改进,该砂磨机由机架、主轴支撑组件、搅拌磨碎机构、冷却循环系统4部分组成,搅拌磨碎机构由研磨盘与分离转子组成。研磨盘的轮毂与外周环形盘由3根轮辐支撑,轮辐起到棒销的作用,从而使其具备盘式砂磨机和棒销砂磨机的效果;缸筒内圆柱表面加工出半圆形的螺旋槽,缸套外圆柱面与缸体内圆柱表面配合连接,形成截面为半圆形的螺旋槽冷却循环通道,避免冷却水循环短路,冷却效果较好。     

PVC制品废料磨粉机磨盘的研制

通过对磨粉机工作原理和磨盘的结构设计分析,提出磨盘设计的关键要素,为磨盘的维修再加工提供了可靠的依据,经过多年的实际应用,取得了良好的效果.     

基于PVC制品废料磨粉机磨盘的研制与应用

分析磨粉机工作原理和磨盘的结构设计,找出磨盘结构的关键尺寸和技术难点,为磨盘的维修再加工提供了可靠的依据,经过多年的实际应用,取得了良好的效果。     

串联式磨盘螺杆挤出机一步法挤出成型木塑复合材料的研究

对串联式磨盘螺杆挤出机一步法挤出成型木塑复合材料进行了实验研究，探讨了植物纤维种类、木粉填充量对复合材料力学性能的影响，并在相同配方的条件下对磨盘挤出机和异向平行双螺杆挤出机加工的木塑复合材料的力学性能进行了比较。研究结果表明串联式磨盘螺杆挤出机更适合于高填充木塑复合材料的挤出成型加工。     

金刚石品级与分布密度对磨盘使用性能的影响

以600目金刚石微粉磨盘为对象,通过磨削加工水晶的试验,研究了金刚石品级、分布密度对磨盘使用性能和质量稳定性的影响.     

新型碳化硅基体单层CVD金刚石磨盘的制备

金刚石磨盘被广泛应用在脆硬材料加工领域。文章将机械粉碎法加工而成的金刚石磨料混入光刻胶溶液中,通过甩胶机将光刻胶均匀地甩在碳化硅基体表面以使磨料均匀分布在基体表面。再利用热丝化学气相沉积法(Hot filament chemical vapor deposition,HFCVD)在金刚石磨粒与碳化硅磨盘基体之间沉积一层金刚石薄膜并将其连结起来,制造出碳化硅基体单层CVD金刚石磨盘。由于生长的金刚石涂层与磨粒和基体间均可形成牢固的化学键结合,因此磨粒与基体间具有较强的结合力。对磨盘进行了对磨试验以检测磨盘与磨粒的结合强度。在SEM下观察到金刚石磨料和基体通过金刚石涂层连接,磨料晶粒得到了修补和生长,粒度长大约8~9μm,针状和片状的金刚石晶粒经过CVD法生长后晶粒饱满度值提高,变得晶型完整,自形面清晰。拉曼光谱检测结果显示生长后的磨粒金刚石峰尖锐,石墨峰低,表明金刚石纯度高、缺陷少、石墨及非晶碳含量很少。在对磨试验中,CVD金刚石磨盘磨粒脱落现象远少于电镀磨盘,表明CVD金刚石磨盘对磨料有高的把持力。CVD金刚石磨盘的磨粒裸露度高,对磨后粘连的磨屑不易发生堵塞。磨粒的断裂、破碎、磨钝现象都显著少于电镀金刚石磨盘。     

我公司JLM4.6立磨磨盘结构的优化

我公司JLM4.6立磨于2008年8月投入生产,磨机主电机装机功率2 600 kW,主减速器JLP250G-WX1,磨机设计能力260 t/h,设备至今运行正常,主机运行功率2 100 kW。磨盘是辊式磨的主要粉磨部件之一,磨盘的主要功能就是支撑料床,将磨辊产生的力传输至下部的减速机,以及将减速机的扭力传输至粉磨区域。物料落到分散板上后,由于离心力的作用,向四周均匀散开,进入磨辊和磨盘之间的粉磨区域进行粉磨。随着水泥生产线产能的提高,磨盘作为大型铸钢件尺寸越来越大,重量越来越重,有的磨盘直径达6 m,重量超过了10 t。这样,大型磨盘受铸造能力、机床加工范围的制约越来越明显,因此磨盘结构急需优化。     

超精密表面研抛磨粒的研究进展

半导体材料的超精密加工是一种获得高表面质量和表面完整性的加工技术,研抛磨粒是实现半导体材料超精密加工的关键耗材之一。从研抛磨粒的组成方式和结构特点,概述了研抛磨粒的研究现状和发展趋势。首先,构建了研抛界面内半导体材料工件-研抛磨粒-研抛垫的接触模型,讨论了研抛磨粒的材质、形状、浓度、粒径等因素对半导体材料研抛质量和研抛效率的影响;其次,从材质和粒径等方面介绍了混合磨粒的研抛性能,以及相应的研抛机理;然后,从材料结构和化学作用等角度总结了复合磨粒在超精密加工技术中的应用;最后,展望了研抛磨粒未来的研究方向。     

YAG晶体研磨工艺与研磨后亚表面损伤研究

YAG晶体是一种典型硬脆材料，莫氏硬度达8.5，常温下不溶于任何酸碱，加工难度较大。针对YAG晶体研磨加工，本工作提出一种分步研磨工艺。基于游离磨料研磨的方法，在研磨过程中逐级减小碳化硼(B₄C)磨料粒径，选用磨料W40、磨料W28、磨料W14、磨料W7分步骤研磨，4种磨料的粒度范围依次为：40～28μm、28～20μm、14～10μm、7～5μm。通过研磨参数试验研究了每个步骤中研磨压力、研磨盘和摆轴转速、研磨液中B₄C质量分数等参数对研磨效果的影响，得出最佳研磨参数；通过截面显微法测量出YAG晶体研磨后亚表面损伤的深度，确定后续抛光去除量，并探究了亚表面损伤深度h _SSD与研磨后表面粗糙度R_a的关系。研究表明：当研磨压力为44.54 kPa、研磨盘和摆轴转速为60 r/min、研磨液中B₄C质量分数为15%时，每个研磨步骤均取得最好研磨效果：磨料W40、磨料W28、磨料W14、磨料W7研磨的材料去除率分别为83.12、57.32、27.54、9.53μm/min，研磨后表面...     

基于拉伸流动的串联磨盘挤出机设计与数值模拟

基于拉伸流动机理对传统串联磨盘挤出机磨盘端面形状进行了结构改进,并借助于计算流体动力学软件Polyflow对磨盘混炼段进行了数值仿真,对比分析了锥面磨盘与普通磨盘的剪切速率、拉伸速率、瞬时拉伸混炼效率和平均拉伸混炼效率及锥面磨盘间隙和凸棱高度对锥面磨盘拉伸流场大小的影响。结果表明,与普通磨盘相比,锥面磨盘形成的收敛流道内熔体粒子主要作无旋流,受到更大的拉伸流场和剪切流场作用,可以获得更高的瞬时拉伸混合效率和时间平均拉伸混合效率;锥面磨盘要获得较强的拉伸流场,存在最佳磨盘间隙和凸棱高度。     

新型玻璃纤维增强树脂薄型切割片的研发

在固定的成型工艺和烤制工艺下,通过对玻璃纤维增强树脂薄型切割片配方体系的调整,涉及磨料、树脂和填料的筛查,研发出一种新型的玻纤增强树脂薄型切割片,主要开发的是115mm×1.2mm×22.2mm产品,其体积小,用料少,有利于减少资源的损耗。切割过程无粉尘污染,符合国家环保政策,有一定的社会效益。该产品是一种高锋利度薄型切割片,能切Φ12.7mm的圆钢,产品的切割性能比常规薄片提高了50%,平均切割时间要快近1s,切割手感锋利,切割效率高,而且价格低廉,市场前景广阔,有着一定的经济效益。     

砂带搭接技术的研究

以FN-309胶粘剂等为接头胶,耐水砂布、全树脂砂布和动物胶砂布等作材料,制作搭接砂带工艺的研究。试验了温度、压力、设备等因素对接头性能的影响。证明该胶在采用搭接技术的情况下作为耐水砂布、全树脂砂布和动物胶砂布接头胶是可行的。     

Manufacture of ethyl silicate-bonded ceramic abrasive elements for disk mills from thixotropic mixes

Strong and wear-resistant ceramic abrasive elements are proposed for groundwood disk mills. They include several large-sized structural elements, one of them of irregular shape. The elements are cast from thixotropic mixes, using ethyl-silicate bond and ordinary alkaline-earth-oxide frits. Translated from Steklo i Keramika, No. 4, pp. 16–18, April, 1997.     

Synthesis and two-step sintering behavior of sol–gel derived nanocrystalline corundum abrasives

Nanocrystalline corundum abrasive with mean crystal size of less than 100 nm was synthesized by two-step sintering method using sol–gel process. A remarkable suppression of grain growth was achieved by controlling sintering temperature and taking advantage of sintering aids during the final stage of a two-step sintering process. The grain size of the high densification samples (>99% theoretical density) produced by two-step sintering method was about 10 times less than the samples made by the conventional sintering technique. The microstructure of the samples was homogeneous without abnormal grain growth and the sol–gel derived corundum abrasive with two-step sintering technique exhibited excellent mechanical properties and wear resistance compared to those sol–gel derived corundum abrasive with conventional sintering methods and fused corundum abrasive.     

Plasma polymerized protective films for plated magnetic disks

Plasma polymerized protective films (PPP films) for magnetic disks have been investigated in order to improve weak durability of plated disk media to head friction and clash. The thickness heterogeneity of PPP films within 5% was realized around the all surface of 140 mm^? model substrates, determining the best discharge condition and apparatus geometry, which did not exert and aggravating influence upon head floating. The friction coefficients of PPP films to a ferrite slider of 0.3 ～ 0.4 were obtained in the thickness of above near 1500 Å, although PPP films are composed of hydrocarbon or fluorocarbon. As the results of contact start/stop cycle tests by a floating head, plasma polymerized toluene-2,4-diisocyanate films show good abrasive durability because of its superior adhesiveness to metal substrates, and PPP films in small thickness near 1000 Å give good protective films. The result of read/write tests indicated that the magnetic deterioration and instability of plated disk media did not occur by the process of plasma polymerization.     

金刚石化学镀镍预处理工艺的改进

为了改进金刚石切割片中的树脂结合剂与磨粒之间相互的粘结程度,以希望达到覆着刺状金属层效果,文中对金刚石化学镀的预处理工艺进行了优化改进。采用了将金刚石粉末加入铬酸洗液中进行浸泡11 h的亲水处理,选择了离子钯活化液实现活化处理。实验结果表明:未经亲水化处理的镍-磷镀层,部分晶面出现漏层现象,而亲水处理过的镀层无此现象;改进工艺能够实现凹凸不平的较厚的镀层的形成;酸性镀液的沉积速率相对较快,但采用该镀液获得的镀层的形貌大都平整光滑,很少出现刺状镀层,碱性镀液沉积速率虽然较低,但施镀温度低,镀液络合稳定常数较高,镀液更稳定,且在碱性镀液中更容易实现人造金刚石表面的刺状镀层的获得。     

Polishing behaviors of ceria abrasives on silicon dioxide and silicon nitride CMP

The effects of ceria (CeO₂) abrasives in chemical mechanical polishing (CMP) slurries were investigated on silicon dioxide (SiO₂) and silicon nitride (Si₃N₄) polishing process. The ceria abrasives were prepared by the flux method, using potassium hydroxide (KOH) as the grain growth accelerator. The primary particle size of the ceria abrasives was controlled in the range of ~ 84-417 nm by changing the concentration of potassium hydroxide and the calcination temperature without mechanical milling process. The removal rate of silicon dioxide film strongly depended upon abrasive size up to an optimum abrasive size (295 nm) after CMP process. However, the surface uniformity deteriorated as abrasive size increases. The observed polishing results confirmed that there exists an optimum abrasive size (295 nm) for maximum removal selectivity between oxide and nitride films. In this study, polishing behaviors of the ceria abrasives were discussed in terms of morphological characteristics.     

纳米TiO2对PTFE基复合材料磨粒磨损性能的影响

利用自行改制的销-盘式磨粒磨损试验机测定纳米TiO2用量对聚四氟乙烯（PTFE）复合材料试件在干摩擦滑动条件下的磨粒磨损性能。考察了载荷、磨粒、转速等参数的变化对试件摩擦学性能的影响。结果表明，在实验条件下，纳米TiO2／PTFE复合材料的抗磨粒磨损性能，以纳米TiO2质量分数为2％时，填充PTFE复合材料抗磨损性能最好。随纳米TiO2用量的增大，抗磨损性能有所减弱。在载荷、磨粒、转速等参数的变化对PTFE复合材料耐磨性的影响中，磨料粒度对磨损的影响最大，转速的影响最小。     

Investigation on thermal stability and tribological properties of ZrB2 particles filling cyanate ester resin composites by experiments and numerical simulation

The thermal stability and tribological properties of cyanate ester (CE) composites filled with Zirconium boride (ZrB₂) particles were investigated by experimental and numerical simulation. The results of thermogravimetric analysis and differential scanning calorimetry showed that the thermal stability of composites was improved by introduction of ZrB₂ particles. The tribological properties of composites including friction coefficient and wear rate measured by pin‐on‐disk friction and wear tester were enhanced. Friction coefficient and wear rate of composites were decreased significantly with an increase of ZrB₂ particles content under dry and oil sliding conditions. The 5 wt% ZrB₂ particles reinforced CE resin composite presented optimal thermal stability and tribological performance due to good dispersion of ZrB₂ particles. The worn surfaces of composites were observed by scanning electron microscopy to explore wear mechanism, indicating that the dominant wear mechanism of composites was transformed from adhesive wear to abrasive wear after incorporation of ZrB₂ particles. Finite element model was established to study the distribution of friction stress. The results revealed that filling ZrB₂ particles in the friction process of composites could bear more friction stress than CE resin matrix, which further illustrated that abrasive wear is main wear mechanism of ZrB₂/CE resin composites. POLYM. ENG. SCI., 59:602–607, 2019. © 2018 Society of Plastics Engineers