烧结温度对陶瓷结合剂金刚石砂轮性能的影响

以金刚石和陶瓷结合剂为原料,以制备的陶瓷结合剂金刚石砂轮为研究对象,研究了烧结温度对其性能的影响.金刚石的热重(TG)和差示扫描量热(DSC)以及陶瓷结合剂的DSC、X射线衍射(XRD)和流动性的分析,确定陶瓷结合剂金刚石砂轮试样的烧结温度上限.通过对陶瓷结合剂金刚石砂轮试样的XRD、扫描电子显微镜(SEM)、开口气孔率、弯曲强度和洛氏硬度的检测和分析,研究其最佳的烧结温度和微观结构.结果表明,实验所用的金刚石开始氧化温度为662.13℃,完全氧化温度为888.00℃.陶瓷结合剂的玻璃转化温度是774.03℃.烧结温度在740℃时,陶瓷结合剂未与金刚石发生化学反应.温度升高时,结合剂的流动性增大,陶瓷结合剂金刚石砂轮试样的开口气孔率也增大.在烧结温度为700℃时,试样的弯曲强度(84.11 MPa)和洛氏硬度(87.66 HRB)达到最大值,金刚石之间的结合剂"桥"更致密,结合剂与金刚石之间润湿性更好,形成有合适气孔的整体.     

氧化钛对陶瓷结合剂金刚石磨具性能及结构的影响

探讨了氧化钛对Li-B-Al-Si系陶瓷结合剂金刚石磨具性能及结构的影响。测试了在完全烧结状态下的陶瓷结合剂金刚石磨具试样的洛氏硬度、抗弯强度、气孔率及显微结构。结果表明:氧化钛含量为0.5wt%时,完全烧结温度下降了20℃,其洛氏硬度为122HRE,断裂强度为68.5MPa。结合剂中的微晶数量没有随氧化钛添加量的增加而增加,而是没有明显变化,因此在加入氧化钛晶核剂的同时应加入一定量的RO氧化物。     

纳米AlN对低温陶瓷结合剂金刚石磨具结构与性能的影响

文章探讨了纳米AlN对Na2O-B2O3-SiO2硼硅酸盐玻璃体系陶瓷结合剂金刚石磨具结构与性能的影响.在不同气氛条件下烧结的陶瓷结合剂金刚石磨具试样,利用万能压力试验机、洛氏硬度计、扫描电子显微镜等仪器,测试磨具试样的抗折强度、洛氏硬度、耐磨性,以及显微结构等.结果表明:纳米AlN含量为6wt%时,结合剂的开始熔融温度为670℃,比纯结合剂低10℃,且烧结温度范围增大;在氩气气氛下烧成,金刚石磨具试样的抗折强度、洛氏硬度、耐磨性等,比在大气气氛下烧成磨具的均有所提高,其中折强度为60.46MPa,洛氏硬度为88;由SEM图谱可以看出,加入纳米AlN后,结合剂与磨粒间结合良好,且组织均匀.     

烧结温度对低温陶瓷结合剂性能的影响

文章研究了不同烧成温度下低温结合剂的烧结范围、强度、硬度,用XRD和SEM对不同烧成温度下陶瓷结合剂金刚石的结构进行了分析.结果发现:试验陶瓷结合剂在开始软化点725℃最适合陶瓷结合剂金刚石磨具的烧成,在该温度下烧成结合剂呈比较均匀的玻璃状态,对金刚石磨粒的润湿性好;在725℃烧成,结合剂的流动性为120%;结合剂试样的弯曲强度和洛氏硬度最大,分别为58.5MPa和93.5(HRA).     

陶瓷结合剂金刚石砂轮的制备研究

陶瓷结合剂金刚石砂轮广泛运用于磨削加工,文章研究了金刚石粒度、烧结温度及结合剂含量对陶瓷结合剂金刚石砂轮性能的影响.研究结果发现金刚石表面微观结构呈多孔状,粒度越细,烧结过程中与结合剂的反应活性越低,砂轮硬度越高.同时在一定范围内烧结温度越高,结合剂含量越低,砂轮硬度越高.     

无机溶胶陶瓷结合剂的制备与研究

以硅溶胶、铝溶胶及化学纯H_3BO_3、NaNO_3、LiNO_3为原料,以溶胶凝胶法制备Al_2O_3-B_2O_3-SiO_2-R_2O体系无机溶胶陶瓷结合剂,并以金刚石为磨料,采用喷雾干燥法制备金刚石-陶瓷复合粉体,后经干燥、压制、烧结制得金刚石-陶瓷复合烧结体。利用X射线衍射仪、TG-DSC、扫描电镜、抗折试验机等表征手段对无机溶胶陶瓷结合剂的物相组成、显微形貌、复合烧结体断面形貌及抗弯强度等进行分析。结果表明,820℃/1h下进行烧结,以此配方制备的无机溶胶陶瓷结合剂结构均匀,且可熔融为液相并对金刚石进行较好地包覆。随着陶瓷结合剂含量的增加,金刚石-陶瓷复合烧结体的抗弯强度随之提高,而气孔率随之降低,且当结合剂含量为30wt%时,抗弯强度和气孔率分别为95.42MPa和34.36%。     

添加剂对低温烧结95氧化铝陶瓷性能的影响

采用MnO2-TiO2-CaO-La2O3复相添加剂作为氧化铝陶瓷的烧结助剂,研究了MnO2添加量对95氧化铝陶瓷烧结性能、力学性能和微观结构的影响。结果表明:当配方中MnO2含量为3.0%时,在1550℃烧结温度下制得的氧化铝陶瓷的综合性能最佳,烧结试样的体积密度达到3.76g.cm-3,试样的抗弯强度和洛氏硬度(HRA)分别达到355.22MPa和84.3。     

烧结工艺对铁基结合剂金刚石节块力学性能的影响

本文研究了热压烧结中烧结温度和烧结压力对铁基结合剂金刚石节块力学性能的影响.实验结果表明:烧结温度对金刚石节块的硬度和抗弯强度等力学性能影响显著;而烧结压力对金刚石节块的抗弯强度和硬度的影响小于温度对二者的影响;节块的应力-应变曲线具有陶瓷的特性.     

MnO2-TiO2-CaO-La2O3复相添加剂对低温烧结氧化铝陶瓷性能的影响

采用MnO2-TiO2-CaO-La2O3体系复相添加剂作为氧化铝陶瓷的烧结助剂,采用模压成型工艺,研究了不同的烧结温度对95氧化铝陶瓷性能的影响.采用XRD和SEM对氧化铝陶瓷试样的晶相组成和微观形貌进行了表征.结果表明,在1450℃烧结时,样品已基本烧结致密,样品的综合性能指标最佳,收缩率为28.5％,体积密度达到3.78 g·cm-3,抗弯强度达到357.12MPa,洛氏硬度值达到78.0.     

纳米陶瓷结合剂超硬磨具的制造工艺

纳米陶瓷结合剂是一种新型的超硬磨具结合剂,采用它能显著降低磨具烧结温度,大幅度提高制品的强度、韧性和耐磨性,且气孔可控,为陶瓷结合剂的应用开拓了一个崭新的领域.文章阐述了纳米陶瓷的性能及应用.结果表明:纳米陶瓷结合剂抗折强度高于100MPa,经过烧结,纳米陶瓷结合剂与金刚石和cBN超硬磨料润湿性良好、结合力大,在烧结过程中与超硬磨料不发生反应、不腐蚀损伤超硬磨料.成功用于磨削PCD复合片的金刚石陶瓷砂轮.     

Fabrication of New Porous Metal-Bonded Grinding Wheels by Hip Method and Machining Electronic Ceramics

Grinding wheels with different abrasive grains and different bonding materials were fabricated using hot isostatic press (HIP) sintering. Poly-crystal diamond powder of #1000 mesh size, single-crystal diamond powder of #1000 mesh size, and synthetic single-crystal diamond abrasive grains of #325 mesh size were used as abrasive grains. Cast-iron, and two different particle sizes of iron powders were used for the bonding material. The grinding capacity of these grinding wheels as well as conventional grinding wheels was evaluated by constant-pressure-grinding method to grind Al₂O₃-TiC component ceramics, which are typical electronic ceramics used for magnetic memory devices. The hardness of the bonding materials, the adhesion strength between abrasive diamond grains and the bonding materials, and the porosity of sintered body strongly relate to the grinding capacity. The porous bonded grinding wheels showed higher grinding capacity than the conventional wheels. The HIP method enables to fabricate excellent porous metal-bonded grinding wheels.     

Fabrication of porous structure vitrified bond diamond grinding wheel via direct ink writing

Porous vitrified bond grinding wheels with complex structure, high porosity, controllable pore size have fundamental application in high efficiency and precision grinding of hard and brittle materials. In this paper, direct ink writing (DIW) is proposed to fabricate three kinds of grinding wheels, including solid structure, triangle structure, and lattice structure. Moreover, the rheological property of ceramic ink with different doses of xanthan gum (XG) solution was investigated to ensure printability, demonstrating 3% XG solution can meet requirements. Additionally, the effect of sintering temperature and pore former (PMMA) contents on size shrinkage rate, morphology, mechanical strength, and porosity et al. were studied. The results indicate that the diamond grinding wheel with 30 vol% PMMA and sintered at 670 °C possess the best comprehensive performance. Besides, grinding performance was evaluated by surface morphology, surface roughness, and material removal rate. Among the DIW-fabricated wheels, triangle structure grinding wheel and lattice structure grinding wheel possess a higher material removal rate than solid structure grinding wheel. Therefore, the porous structure grinding wheels fabricated by DIW present the advantage of controllable porosity, excellent self-sharpening ability, and higher bond strength, which may pave the way for designing a new generation vitrified bond diamond grinding wheel.     

原料预合金化对微波无压烧结金刚石工具性能的影响

以Fe₆₀Cu₄₀预合金粉和单质粉为基础原料,利用微波无压烧结在850 ℃制备了FeCu/WC基金刚石复合材料刀头。通过探讨物料在微波场中的升温特性设计了微波无压烧结制度。采用扫描电子显微镜（SEM）、万能试验机、激光拉曼光谱等表征手段,对比研究了预合金粉和单质粉微波烧结样品的组织形貌等微结构信息,并获得了样品的硬度、致密度、横向断裂强度等力学性能。结果表明,与常规烧结方法相比,微波强化烧结可将温度降低至900 ℃以下,金刚石颗粒没有出现石墨化转变;FeCu/WC基配方在850 ℃微波烧结样品的洛氏硬度、相对致密度、横向断裂强度分别达到102.7 HRB、98.5%、1 035 MPa。并对微波烧结的强化机制和原料预合金化对于基体的增强机理进行了初步探讨,微波无压烧结对于预合金粉体金刚石刀头的制备表现出良好的应用前景。     

烧成温度对MgO-TiO2复合无机陶瓷微滤膜支撑体性能的影响

采用添加造孔剂高温烧结法制备了氧化镁-二氧化钛（MgO-TiO₂）复合无机陶瓷微滤膜支撑体。分别研究了相同烧结制度下不同最高烧结温度、相同最高烧结温度不同的烧结制度下样品的孔隙率、抗弯强度及纯水通量的变化情况。采用热重分析（TG-DSC）、电子扫描电镜（SEM）和万能试验机等对样品进行热分析、观察样品形貌及抗弯强度等性能测试。研究表明,最高烧结温度和烧结制度对样品的性能有很大影响,采用最高烧结温度为1 400 ℃、升温速率分别为4、8、2 ℃/min的1400-482烧结制度所制备的支撑体的性能最佳,孔隙率为37.57%,抗弯强度为108.65 MPa,纯水通量为4 040 L/（m²?h?MPa）。     

微波强化烧结制备铁钴基金刚石锯片刀头

采用微波烧结技术制备了低钴型Fe-Co基金刚石锯片刀头,利用圆柱谐振腔微扰法电磁特性测试系统评价了配方物料压坯的吸波特性,并结合物料在微波场中的升温特性设计了可行的微波烧结制度。采用SEM、致密度和硬度测试对比研究了微波烧结和常规烧结所得样品的微结构信息和力学性能。结果表明,对于低钴高铁型配方,在850℃下微波烧结获得的样品,其相对致密度和硬度即可分别达到96.63%和99.4HRB,微波烧结在最大升温速率为32.5℃/min时能保证烧结体组织均匀。与常规烧结方法相比,在获得同等级力学性能的前提下,微波强化烧结可将温度降低至900℃以下,显著缩短了烧结总时间,在金属基金刚石工具刀头烧结方面表现出良好的应用前景。     

陶瓷结合剂金刚石磨具用于陶瓷干磨的探索

对比了三种不同结合剂的金刚石磨边轮在陶瓷砖边棱干法磨削工序中的使用情况。实验表明,树脂结合剂磨具磨损快并易在陶瓷砖上产生黑痕,金属结合剂磨具易发生粘刀现象而且被磨陶瓷砖表面光洁度低,相比之下,在同样的工况条件下,陶瓷结合剂磨具既不产生黑痕,能得到较好的表面光洁度,又有较好的自锐性。说明陶瓷结合剂金刚石磨具比较适合于陶瓷砖干磨工序。     

碱金属氧化物Na2 O对陶瓷结合剂金刚石磨具性能的影响

通过调整陶瓷结合剂中碱金属氧化物Na₂O含量,来探究碱金属氧化物Na₂O对陶瓷结合剂金刚石磨具性能的影响。当n(Na₂O)/n(SiO₂)=0.1时,磨具试样的强度(57.7 MPa)和硬度(117 HRB)达到最大值。随着碱金属氧化物Na₂O添加量的增加,结合剂的耐火度随之显著降低,流动性显著增加。磨具试样断口SEM照片表明,适量的碱金属氧化物Na₂O能够使磨具断面空隙减少,孔隙度降低,结合剂与磨料分布更加均匀,结合剂与磨料结合界面更加紧密。XRD分析表明,磨具试样在720 ℃下烧结,结合剂中除了玻璃相还产生了一种晶相,结合剂中碱金属氧化物Na₂O的含量对烧结后产生的晶相种类无影响。     

SOME PHYSICAL PROPERTIES OF ARTIFICIAL ALUMINOUS ABRASIVES1

Specimens representing six different bond compositions in soft, medium, and hard grades of artificial aluminous grinding wheels were tested for various physical properties such as hardness, elasticity, expansion, mechanical endurance, impact strength, etc. It was found that the expansion of present commercial grinding wheels and abrasive bonds is much less than that of artificial corundum. The strength of the wheels increases greatly with increasing percentages of bond. The methods of making the various physical determinations are given along with their interpretation.     

Sintering,microstructure, and mechanical properties of vitrified bond diamond composite

The demand for high-performance grinding wheels is gradually increasing due to rapid industrial development. Vitrified bond diamond composite is a versatile material for grinding wheels used in the backside grinding step of Si wafer production. However, the properties of the vitrified bond diamond composite are controlled by the characteristics of the diamond particles, the vitrified bond, and pores and are very complicated. The main objective of this study was to investigate the effects of SiO₂–Na₂O–B₂O₃–Al₂O₃–Li₂O–K₂O–CaO–MgO–ZrO₂–TiO₂–Bi₂O₃ glass powder on the sintering, microstructure, and mechanical properties of the vitrified bond diamond composite. The elemental distributions of the composite were analyzed using electron probe micro-analysis (EPMA) to clarify the diffusion behaviors of various elements during sintering.The results showed that the relative density and transverse rupture strength of the composite sintered at 620 °C were 91.7% and 126 MPa, respectively. After sintering at 680 °C, the glass powder used in this study exhibited a superior forming ability without an additional pore foaming agent. The relative density and transverse rupture strength of the composite decreased to 48.2% and 49 MPa, respectively. Moreover, the low sintering temperature of this glass powder protected the diamond particles from graphitization during sintering, as determined by X-ray diffraction and Raman spectrum. Furthermore, the EPMA results indicate that Na diffused and segregated at the interface between the diamond particles and vitrified bond, contributing to the improved bonding. The diamond particles can remain effectively bonded by the vitrified bond even after fracture.     

气压烧结TiB2-Al2O3复相陶瓷的显微结构与力学性能

以2.5%(质量分数,下同)Ni为助烧剂,用气压烧结方法分别制备了含20%,30%和50%Al2O3的TiB2-Al2O3复相陶瓷.通过扫描电镜观察样品的形貌,并研究了Al2O3含量对材料显微结构和力学性能的影响.结果表明:金属Ni能有效地促进材料的致密化;随着Al2O3含量的增加,材料的致密度、抗弯强度和断裂韧性增加,弹性模量出现峰值,Vickers硬度降低,Rockwell硬度变化不大.在加入30%Al2O3时,得到了显微结构均匀,性能较好的TiB2-Al2O3复相陶瓷,其抗弯强度可达520MPa,弹性模量达339GPa,Rockwell硬度达92.6.