粉末冶金陶瓷模工艺中的快速脱蜡新技术

粉末冶金陶瓷模工艺是一种先进的过净形成形工艺．本文报道该工艺中一种新的脱蜡技术．采用快速加热、管径集中热量和定向导热传热综合方法，在陶瓷模和大部分蜡模材料处于较低温度下，使蜡模材料来不及发生显著的热膨胀而直接蒸发，得到脱蜡干净、外形完整的陶瓷模．     

A New Shaping Model for Green Ceramic Balls

The shaping quality of green ceramic balls is directly related to the efficiency and cost of later machining for the ceramic balls. Until now the shaping for green ceramic balls is still conducted by handwork. In this paper, a new shaping model for green ceramic balls was designed. In the new model, two grinding wheels with the same generator line as circular arc are mounted on symmetry, and their axes are parallel. The green ball can be put in the enveloping space formed by the two grinding wheels. The rad...     

Study on Ceramic Cutting by Plasma Arc

Engineering ceramics are typical difficult-to-machine materials because of high hardness and brittleness. PAC (Plasma Arc Cutting) is a very important thermal cutting process and has been successfully used in cutting stainless steel and other difficult-to-machine alloys. PAC‘s application in cutting ceramics, however, is still limited because the most ceramics are not good electronic conducts, and transferred plasma arc cannot be produced between cathode and work-piece. So we presented a method of plasma ...     

关于碳化硅作为超低碳钢连铸结晶器保护渣熔速调节剂的研究

本文研究了碳化硅（SiC）作为保护渣熔速调节剂的特性及作用机理,研究表明,以SiC替代炭质材料可大大降低保护渣对超低碳钢连铸坯的增碳和渗碳量。     

新型压电陶瓷涡街流量计

介绍一种新型的压电陶瓷涡街流量计,该流量计采用ＢＳＴ压电陶瓷元件来检测旋涡释放频率,使该流量计能在高温工况下工作,一年多的工业现场运行试验结果表明,新研制的涡街流量计可靠性高、稳定性好,在４００℃高温和１０ＭＰａ高压下能长期连续正常运行。     

激光烧结陶瓷粉末成形零件的研究

实验研究了Ａｌ２Ｏ３陶瓷粉末的激光烧结过程,介绍了激光烧结实验装置,分析了烧结参数对烧结过程的影响,得到了激光烧结的Ａｌ２Ｏ３陶瓷零件。所设计的实验装置的结构简单,可满足实验要求。     

ZrO2陶瓷材料在水环境中的疲劳断裂特性

采用断裂力学中的四点弯曲试验法 ,对 Zr O_2 陶瓷材料分别在大气、水环境中的静疲劳和循环疲劳破坏特性进行研究 ,通过扫描电子显微镜 (SEM)对试验片断裂面的微细组织进行观察 ,分析并阐明了造成材料疲劳断裂的机理 .结果表明 ,相同应力条件下 ,材料在水环境中的疲劳寿命比大气环境中低以及循环疲劳对材料的疲劳寿命起到劣化作用 ,该劣化作用可以认为是由于循环应力使得微裂纹增加和扩展造成的 .     

陶瓷与金属的氧化物封接料制备及其封接工艺

用混合熔烧的方法，制备出一种氧化物封接料．该封接料能在７００℃下对氧化铝瓷与铜及铜合金进行气密性封接．在封接中，只需将封接料涂在陶瓷体的封接面，套上金属件，在马弗炉中以５℃／ｍｉｎ升温到７００℃后保温１０ｍｉｎ即可．对封接体所作的拉伸强度和气密性质量检测表明，封接界面的抗拉强度高于陶瓷本体强度，界面对空气的漏率小于１．４×１０－９Ｐａｍ３／ｈ，满足工业部门对封接质量的要求．     

Interface bond mechanisms of ceramic-cemented carbide compact insert

Conclusion Ceramic-cemented carbide compact inserts have been developed by hot-pressing sintering techniques, the upper part of the compact insert is of Al₂O₃ + TiB₂ ceramic material, while the base part of the compact insert is of WC + Co cemented carbide. The compact insert makes full use of the advantages of the high hardness of ceramic materials and the high strength of cemented carbide, and its mechanical properties are just between that of Al₂O₃ + TiB₂ and WC + Co. SEM, XRD and electron microprobe analysis showed that element diffusion and formation of new phases are the main causes for the bond of Al₂O₃ + TiB₂ with WC + Co in the interface.     

Si_3N_4-SiC纳米复合陶瓷材料的研究

用粒度为 ５０～７０ ｎｍ的纳米级 ＳｉＣ粉体与微米级的 Ｓｉ３Ｎ４粉体复合来制备 Ｓｉ３Ｎ４－ＳｉＣ纳米复合陶瓷材料，对纳米ＳｉＣ含量不同的Ｓｉ３Ｎ４－ＳｉＣ纳米复合陶瓷材料的微观组织结构与性能的关系进行了研究。结果表明：纳米ＳｉＣ质量分数为１０％时，经热压烧结法制备的Ｓｉ３Ｎ４－ＳｉＣ纳米复合陶瓷材料的抗弯强度为 ８４４ ＭＰａ，断裂韧性为 ９． ７ ＭＰａ· ｍ１／２。微观组织结构的研究还表明，纳米ＳｉＣ的不同含量影响着基体Ｓｉ３Ｎ４的晶粒形貌，从而决定了复合材料的性能。探讨了纳米级ＳｉＣ在基体中的形态、分布及其对基体强化增韧的新机制。