共查询到18条相似文献,搜索用时 78 毫秒
1.
2.
3.
4.
5.
6.
简要介绍了拉伸模的受力状况、性能要求及常用拉伸模具材料,并指出WC-Co硬质合金是目前最常用的拉伸模具材料,分析了该类材料的优越性及存在的问题,同时提出了新型模具材料--Ti(C、N)基金属陶瓷。综述了金属陶瓷的制备工艺、合金元素的作用及微观组织对机械性能的影响,最后强调了Ti(C、N)基金属陶瓷是一种具有广阔应用前景的模具材料。 相似文献
7.
以TiCN-WC-Mo2C-TaC-Co-Ni为原料,通过成分和气氛控制,获得了功能梯度TiCN基金属陶瓷材料。采用带有能谱分析仪的扫描电子显微镜和X射线衍射仪观察和分析了材料的微观组织和物相组成,通过车削实验考察了所制备的刀具的切削性能。结果表明,WC含量较低时,通过气氛控制可以获得表面富Ti层、中间富W层和基体的3层TiCN基金属陶瓷梯度层,烧结温度的提高有利于梯度层的厚度的增加;WC含量较高时,烧结后WC在表面富集。15%WC含量的TiCN基金属陶瓷在1 460℃氮气气氛中烧结1 h时,富Ti层的厚度约为15~20μm,富W层厚度约为15~20μm。经氮化烧结后材料表面的(Ti,W,Mo)(C,N)衍射峰相对材料内部向右偏移。真空烧结时,当WC含量较低时,Ti和W元素分布比较均匀;随着WC含量的升高,表面出现了贫Ti富W层,且随着WC含量增加,表面富W层增厚,WC含量为24%时,富W层厚度25μm。切削实验表明表面富Ti的金属陶瓷的切削性能优于表面富W的金属陶瓷材料。 相似文献
8.
9.
10.
11.
Xiangkui Zhou Kai Wang Zhifeng Xu Qiang Wang Guojian Li Jicheng He 《计算机、材料和连续体(英文)》2014,41(2):153-162
At present, the functionally gradient cemented carbide (FGCC) substrate with enrich cobalt on surface is mainly formed from medium grained WC grains. In order to further improve the properties of gradient cemented carbides, the ultrafine powder was chosen in this study and the functionally gradient cemented carbide with ultrafine grains was prepared by a two-step process, where the cemented carbide is first lower pressure pre-sintered and then subjected to a gradient sintering. The results show that it is possible to form gradient layer with enriched cobalt on surface by this method and also the grain growth can be inhibited by low pressure pre-sintering. Ultrafine grain gradient cemented carbide was fabricated after the gradient sintering, the thickness of gradient layer was about 43μm and the average grain size of WC is about 0.42μm. The formational mechanism of the functionally gradient cemented carbide with ultrafine grains are discussed through analyzing the influence of ultrafine microstructure, which was obtain by lower pressure pre-sintering, on atomic diffusion and grain growth during gradient sintering process. 相似文献
12.
Action of New Rare Earth Additions in Cemented Carbide 总被引:4,自引:0,他引:4
Chenguang LIN General Research Institute for Non-ferrous Metals Beijing China 《材料科学技术学报》1993,9(3):177-184
The existence form and distribution of new rare earth additions in WC-Co,WC-TiC-Co.Cementedcarbide and its actions of purification,modificaiton,solid solution strengthening and restrainingphase transformation have been investigated.The results have been used to elucidate property im-provement of the alloys. 相似文献
13.
14.
Chemical Processing of Nanostructured Cemented Carbide 总被引:1,自引:0,他引:1
Chemical processing is becoming a vital component in the economic development of advanced engineering materials. Our research group on chemical processing has been focussed on the development of process to produce nanophase cemented carbide. It is a much more direct route for making WC/Co than traditional processing methods, and offers the potential for lower cost production of novel materials with homogeneous nanophase microstructures and improved properties. This paper addresses the scientific and technical issues relating to the chemical processing of nanophase WC/Co composite powder and their sintering. 相似文献
15.
16.
17.
表面活性剂对MIM硬质合金粘结剂和喂料性质的影响 总被引:2,自引:0,他引:2
研究了表面活性剂对粘结剂润湿性能和对粘结剂与粉末分离的影响以及表面活性剂对喂料流变性能的影响。结果发现 :表面活性剂的加入 ,可以有效地改善粘结剂的润湿性能和增强粘结剂与粉末的结合力 ,并且可以改善喂料的流变性 相似文献
18.
WC-Co类硬质合金疲劳特性研究现状 总被引:5,自引:1,他引:5
综述了WC-Co类硬质合金疲劳裂纹的产生及扩展特性,指出WC-Co类硬质合金在使用时同时受多种疲劳的共同作用,但疲劳失效的主要形式是不同的,其中在中软岩石层中工作时的疲劳失效主要是由热疲劳引起的,在硬岩石层中工作时的疲劳失效主要是由冲击疲劳引起的.根据文献资料可归纳出:合金显微组织结构(晶粒度)、化学成分(Co量、总碳等)、纯净度(微量元素)和合金残余应力都是影响合金疲劳性能的主要因素,尤其认为Co粘结相的平均自由程是影响合金疲劳性能最主要的因素. 相似文献