共查询到18条相似文献,搜索用时 187 毫秒
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系统总结了近年来研究的Ti(C,N)基金属陶瓷材料的基本成分、制备过程、工艺处理及其组织与性能,阐述了影响Ti(C,N)基金属陶瓷材料性能的因素,提出了改善Ti(C,N)基金属陶瓷材料性能的努力方向. 相似文献
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采用低压烧结的方法制备Ti(C,N)基金属陶瓷材料,并结合C、N、O分析,XRD、BSE、EDS等测试手段研究了SD成型剂对Ti(C,N)基金属陶瓷合金的C含量、相组成及显微结构和力学性能的影响。结果表明,随着SD成型剂添加量的增加,脱胶后压坯的C含量逐渐增加,N含量逐渐减小;烧结后Ti(C,N)基金属陶瓷由(Ti,Me)(C,N)(Me=W、Mo、Ta)和Ni/Co固溶体相组成;显微组织以黑芯-白环结构为主,并伴随着少量白芯-灰环的结构。SD添加量为100mL/kg时,Ti(C,N)基金属陶瓷材料的抗弯强度达1929MPa,硬度为1588HV30,添加量为180mL/kg时,合金组织中石墨相的出现使其抗弯强度大幅度下降。 相似文献
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硬质相粒度对Ti(C,N)基金属陶瓷断裂韧性的影响 总被引:5,自引:0,他引:5
用压痕法测定了具有不同粒度硬质相的Ti(C,N)基金属陶瓷的断裂韧度,结果发现,当成分和制备工艺不变时,Ti(C,N)基金属陶瓷的断裂韧性随硬质相粒度的增大而减小,进一步分析表明,当Ti(C,N)颗粒较粗时,极易发生穿晶断裂,并且裂纹连续穿晶扩展时亦不会发生显著的偏转或分叉,金属陶瓷呈现较强的脆性断裂特征,而当Ti(C,N)颗粒较细时穿晶断裂几率大大减小,裂纹较易沿Ti(C,N)颗粒与粘结相的界面扩展,导致脆性断裂现象减少和裂纹偏转而增韧。产生上述现象的主要原因与Ti(C,N)晶体的结构有关,面心立方结构的Ti(C,N)晶体中可能存在多个潜在的滑移面和滑移系,裂纹从一个Ti(C,N)颗粒扩展至另一个Ti(C,N)颗粒时很容易形成取向有利。 相似文献
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为了进一步提高金属陶瓷的力学性能及其刀具的高速切削性能, 研究了纳米增强金属陶瓷的显微组织特征和热冲击性能。扫描电镜和透射电镜分析表明: 组织中陶瓷相呈现典型的芯2壳结构特征; 芯为TiC 或Ti (C ,N) , 而壳则为( Ti ,Mo ,W) (C ,N) 固溶体。纳米增强金属陶瓷机制为细晶强化、弥散强化和固溶强化。热冲击实验表明: 随着热循环的进行, 材料中孔洞的数量、孔洞的尺寸以及微裂纹的尺寸随之增大; 同时, 热循环过程中出现的表面氧化、裂纹长大、偏转以及桥接现象也很显著。与常规Ti (C ,N) 金属陶瓷相比, 纳米增强金属陶瓷的抗热冲击性能明显提高。 相似文献
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Ti(C, N)-based cermets with addition of SiC whisker (SiCw) were prepared by vacuum sintering. The microstructures of the prepared cermets were investigated by using X-ray diffractometry (XRD) and scanning electron microscopy (SEM). Mechanical properties such as transverse rupture strength (TRS), fracture toughness (KIC) and hardness (HRA) were also measured. It was found that the grain size of the cermets was affected by the SiC whisker addition. The cermets with 1.0 wt.% SiC whisker addition exhibited the smallest grain size. The porosities of the cermets increased with increasing SiC whisker additions. The addition of the SiC whisker had no influence on the phase constituents of the cermets. Compared with the cermets with no whisker addition, the highest TRS and fracture toughness for cermets with 1.0 wt.% SiC whisker addition increased by about 24% and 29%, respectively. The strengthening mechanisms were attributed to finer grain size, homogeneous microstructure and moderate thickness of rim phase. The toughening mechanisms were characterized by crack deflection, whisker bridging and whisker pulling-out. 相似文献
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功能梯度Ti(C, N)基金属陶瓷制备技术 总被引:2,自引:1,他引:1
通过真空液相烧结制备出Ti(C,N)基金属陶瓷基体,并对基体表面进行双辉等离子渗碳处理。运用扫描电子显微镜(SEM) 、电子探针(EPMA)、X射线衍射(XRD)等分析手段对渗碳前后材料的显微组织形貌、成分分布以及物相组成进行分析。结果表明,双辉等离子渗碳后金属陶瓷表面富Ti、Mo、W、C、N元素,贫Ni。渗碳过程中表层高的碳活度驱使内部的Ti、Mo、W元素向外迁移,从而迫使Ni向内迁移。渗碳后,材料表层富硬质相,近表层富粘结相。渗碳处理使试样表层硬度得到提高,对横向断裂强度影响不大。 相似文献
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Changes in the nitrogen content of Ti(C,N)-based cermets during powder mixing and sintering processes were investigated and the denitrification mechanism was re-evaluated. The denitrification of N-containing cermets occurrs mainly during the powder mixing process, and is relatively small during sintering periods. Denitrification during powder mixing is caused by oxidation of the Ti(C,N) powders in contrast to denitrification during sintering, which is caused by the decomposition of the nitrides due to the high nitrogen partial pressure. It was concluded that the main source of oxygen for the powder oxidation was the water present in the ethanol solvent. 相似文献