金刚石圆锯片用铁基与钴基结合剂之比较

本文通过理论分析和有关试验,证明了铁基金属结合剂的机械性能、抗磨损性和对金刚石的把持力能够满足加工花岗石用孕镶刀头的使用要求。当采用抗压强度为13—15Kg的金刚石时,用铁基结合剂制造的大直径金刚石圆锯片可获得不亚于甚至略优于钴基结合剂锯片的锯切性能,而其制造成本相对于后者则有较大的降低。     

金刚石钴基结合剂材料的表面分析

采用表面分析技术研究了金刚石钴基结合剂材料在热压时的表面反应和反应产物的形态及分布，发现结合剂材料与金刚石的结合性能取决于表面反应产物的结构和分布状态．     

钒对金刚石工具新型铜基结合剂组织和性能的影响

通过抗弯强度测试、显微硬度和扫描电镜研究新型铜基结合剂CSF中添加V元素后组织和性能的影响.结果表明:强碳化物形成元素V可与金刚石发生界面反应,富集于金刚石表面,当V质量分数低于4%时,可通过固溶强化显著提升胎体的硬度以及胎体对金刚石的把持力,且把持力随着V的增加而增加;当V质量分数超过4%时,胎体组织不均匀,性能降低,对金刚石的把持力下降.     

新型铜基结合剂金刚石锯片组织和性能的研究

在新型铜基结合剂CSF中加入不同粉末,采用真空热压法和激光焊接法制成金刚石锯片,通过切削试验测定其切削性能,并结合扫描电子显微镜观察其显微组织。结果表明,由CSF烧结的金刚石锯片可顺利进行切削,且Fe、P等元素能一定程度提升结合剂的致密度和硬度;添加铬粉、钼粉的CSF结合剂对金刚石磨粒固着把持能力相比Fe、P-Fe等提升了40%左右,锯片的锋利度更高,切削性能最佳,且磨弧胎体的磨损与金刚石的磨损能保持较好匹配,使用寿命长,优于普通Cu-Sn刚石锯片。     

单晶金刚石在铁基合金中的性态与行为

将金刚石单晶孕镶在Ｆｅ基合金中，在一定条件下烧结，发现金刚石受到明显刻蚀，但晶体结构和强度未变，刻蚀在金刚石与结合剂的界面发生，它是金刚石晶格中的Ｃ原子溶入Ｆｅ，并在其中扩散的过程，适当控制这一扩散过程，将使Ｆｅ基结合剂的金刚石工具获得优良性能。     

单晶金属石在铁基合金中的性态与行为

将金刚石单晶孕镶在Ｆｅ基合金中，在一定条件下烧下，发现金刚石受到明显刻恂，但晶体结构和强度未变，刻蚀在金刚石与结合剂的界面发生，它是金刚石晶格中的Ｃ原子溶入Ｆｅ，并在其中扩散的过程。适当控制这一扩散过程，将使Ｆｅ基结合剂的金刚石工具获得优良性能。     

多孔金属结合剂金刚石砂轮节块的有限元分析

利用十四面体模型描述开孔金属结合剂金刚石砂轮胎体的胞体结构,并用有限元方法确定材料的弹性模量,进而将金刚石以增强颗粒的形式加入胎体材料中,形成开孔结构的金属结合剂金刚石砂轮节块的有限元模型。数值分析了以金刚石为增强颗粒的多孔金属结合剂复合材料在横向剪切载荷下的应力情况。结果表明,多孔金属结合剂金刚石砂轮节块在承受横向剪切载荷下,最大应力发生在胎体上,这与试验中节块断裂往往出现在胎体中孔的棱边上相一致。     

切削工具用烧结材料

淬硬钢、镍基耐热合金和钴基耐热合金等高硬度材料的切削加工,通常用的是钨等高熔点金属的碳化粉末与铁、钴、镍等金属烧结成的超硬合金工具。近年来,由于加工品种不断增加,加工条件更趋严格,开发出了以陶瓷原料与金刚石粒烧结体,或以立方晶系氮化硼(略记CBN)烧结体等材料制造加工工具。但由于烧结金刚石用CBN作为硬质颗粒制成CBN烧结体,因其与铁系金属基本不发生反应,可用于除金刚石以外的所有加工对象,包括淬硬钢和超     

真空条件下钎焊单层金刚石砂轮的研究

单层高温钎焊超硬磨料砂轮具有电镀砂轮无法比拟的优异磨削性能。在真空条件下用Ni-Cr合金做钎料进行了钎焊单层金刚石砂轮的实验研究,实现了金刚石与钢基体间牢固的化学冶金结合。扫描电镜X射线能谱,结合X射线衍射结构分析发现,在金刚石界面上有Cr的碳化物Cr3C2和Cr7C3存在,而钢基体结合界面上则生成有(FexCry)C,这应是金刚石与钢基体之间具有较高结合强度的主要原因,通过磨削实验验证了金刚石确实有很高的把持强度。     

人造金刚石表面金属化新技术

采用磁控溅射离子镀技术在人造金刚石表面镀附μｍ级金属钛膜，该镀层实现了金刚石与金属结合剂的冶金结合，从而提高了金刚石工具的使用效率和寿命，解决了目前镀附设备投资大或单次镀附量少的问题，为推广应用提供了广阔前景。     

Research on a New Type of Diamond Saw Plate

With the developing of stone material, diamond saw pl ate is used widely, and in order to increase cutting efficiency and life-span o f diamond saw plate, there are a lot of research jobs of segment for diamond saw plate. Layered segment for diamond saw plate is to divide single segment into s everal cutting tools by its structure, then increases rock-cutting faces. For i mpregnated man-made diamond saw plate, the bonding strength of diamonds with ma trix material has great effect on its life and service....     

EFFECT OF MODAL COLLOIDAL SUBSTANCES ON THE PROPERTIES OF NEWSPRINT

1.INTRODUCTIONIn modern papermaking of newsprint, pitch and stickies control draws more attention with higher proportion of mechanical pulp and second fibers in furnishes. The accumulation of colloidal substance in process could affect the production and products most introduced by wood containing pulp and sec-ondary fibers. Sources of in-process colloid were complex and extensive, including lignin, hydropho-bic extraction, coating, adhesive and other additives[1-3]. Pitch was more seriou…     

CVD金刚石涂层附着性能研究

采用微波等离子体CVD（MPCVD）法在YG6硬质合金基体表面沉积金刚石涂层，在金刚石的形核和生长阶段分别采用不同的沉积条件，研究了分步沉积工艺对金刚石涂层形核，质量及其附着性能的影响，结果表明：采用分步优化的沉积工艺，可明显改善金刚石涂层与刀具基体之间的附着性能，这主要是由于基体表面形核密度的提高，增大了涂层与基体之间的实际接触面积。     

Si—Ti—B掺杂金刚石／硬质合金复合体的性能

金刚石粒度和掺杂量两因素对Si-Ti-B掺杂金刚石/硬质合金复合体的金刚石层的抗弯强度和耐磨性的综合影响,可以归结为平均自由程与机械性能的关系。在强度(或耐磨性)与平均自由程的关系曲线中,存在最大值。对于低掺杂量材料,强度随平均自由程(粘结相层厚度)的减少而降低。对于高掺杂量材料,强度随粘结相层厚度的增大而下降。Si-Ti-B掺杂烧结金刚石的耐热性高于钴粘结金刚石。     

Valance electron structure of carbide-diamond interface and catalytic mechanism for diamond synthesis under high-pressure and high-temperature

The metallic films surrounding a synthetic diamond formed under high-pressure and high-temperature (HPHT) in the presence of Fe-based and Ni-based catalysts were studied by scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM). It was showed that the carbide was the primary carbon source for the nucleation and growth of diamond. Based on the EET (empirical electron theory in solid and molecules) theory, the valence electron structure of interface between carbide (Fe₃C, Ni₃C, (Fe, Ni)₃C) and diamond was calculated using the bonding length difference (BLD) method. The boundary criterion of Thomas-Fermi-Dirac-Cheng (TFDC): “the electron density being equal on the contacting surfaces of atoms” was applied to analyze the valence structure of carbide-diamond interface. The result based on the calculation valance electron structure is in good accordance with the experimental result. This study is very helpful to reveal the catalytic mechanism of diamond nucleation and growth and design the new catalyst for diamond synthesis.     

平网印花用水溶性逆向反射浆应用性能的研究

通过对以水溶性粘合剂为基础的平网用逆向反射浆性能的研究，试图用水溶性粘合剂取代目前采用较多的以有机溶剂型粘合剂为基础的逆向反射浆。文中研究了由不同颜色组成的反射层对反射效果的影响；研究了微珠的用量、丝网的目数对逆向反射效果的影响；研究了不同类型的水溶性粘合剂及用量对玻璃微珠牢度的影响；研究了表面层的存在对逆向反射织物牢度及逆向反射系数的影响。     

Selective interfacial bonding and thermal conductivity of diamond/Cu-alloy composites prepared by HPHT technique

Cu-based and Cu-alloy-based diamond composites were made by high-pressure-high-temperature (HPHT) sintering with the aim of maximizing the thermal conductivity of the composites. Improvements in interfacial bonding strength and thermo-physical properties of the composites were achieved using an atomized copper alloy with minor additions of Co, Cr, B, and Ti. The thermal conductivity (TC) obtained exhibited as high as 688 W·m-1·K-1, but also as low as 325 W·m-1·K-1. A large variation in TC can be rationalized by the discrepancy of diamond-matrix interfacial bonding. It was found from fractography that preferential bonding between diamond and the Cu-alloy matrix occurred only on the diamond {100} faces. EDS analysis and Raman spectra suggested that selective interfacial bonding may be attributed to amorphous carbon increasing the wettability between diamond and the Cu-alloy matrix. Amorphous carbon was found to significantly affect the TC of the composite by interface modification.