可加工陶瓷结构件的设计优化研究

以云母微晶玻璃陶瓷为研究对象，通过模拟和分析，设计了一种金属热防护系统承力结构件，对可加工陶瓷的结构件进行了优化设计；对可加工陶瓷结构件在热、力载荷以及热力耦合下的陶瓷承力件的热流、温度以及应力的分布进行了分析。通过优化调整结构件的形状，最大应力值分别降低了14．8％和30．64％，最大热流值分别降低了7．65％和6．73％。分析表明，此种模拟方法，能够直观的考察结构件内部在各种载荷下的参数分布，并通过优化，可获得理想的结果。     

三元层状可加工陶瓷Ti_2AlN的研究进展

对三元层状可加工陶瓷Ti2AlN的电子结构及其力学、抗氧化和热电等性能方面的研究进行了综述。重点阐述了Ti2AlN与Ti2AlC相比,其断裂韧性和维氏硬度较低而电导率较高的原因,介绍了Ti2AlN的制备现状与应用前景。     

不同掺杂对可加工陶瓷二次电子发射及沿面闪络特性的影响

固体绝缘材料的表面特性极大地影响着其真空沿面闪络特性,长期以来这一现象极大地制约着真空绝缘系统的整体性能,限制了高压电真空设备的发展进程.本文针对一种具有良好加工性能及表面耐电特性的低熔点可加工微晶玻璃陶瓷引入真空绝缘的背景,在不明显降低可加工性能的前提下,通过在可加工陶瓷原材料内掺杂不同的低二次电子发射系数金属氧化物...     

机加工对陶瓷性能的影响机理及可加工陶瓷材料

由于陶瓷属于脆性材料,在机加工过程中易引入微裂纹等非本征缺陷和残余应力等机加工缺陷,从而造成材料损伤。通过改善陶瓷材料的显微结构,可设计和研制出有可加工性的陶瓷材料。对玻璃陶瓷、Ti3SiC2、Si3N4、SiC及氧化物陶瓷等多种可加工陶瓷材料进行了简单介绍。     

Microstructure and Properties of CePO4 Ceramic

Cerium phosphate powders were synthesized by direct solid liquid reaction of cerium dioxide and phosphate acid at the Ce ： P ratio of 1 ： 1. Phase-pure and fine grain size CePO4 powers could be obtained by calcining the as received powders at the temperature higher than 600 ℃ . It is demonstrated that the grain size and morphology of the CePO4 powders were calcined at various temperatures. An interesting layered crystal structure and a series of microcracks that cross and occur along the extrusion stress direction on the extruded surface inside CePO4 were observed. The ductility and machinabililty of CePO4 ceramic are attributed to the layered structure. Continuous machining debris was observed on the turned surface.     

精密喷射成形用的可加工锆英石/氮化硼底模

为使喷射成型沉积坯底部有模具钢的表面形貌,需要制备上表面有翻制形貌的陶瓷底模.采用硅溶胶预包覆处理的锆英石/氮化硼粉为原料,以硅溶胶为粘结剂,经100 MPa湿压成型、800℃煅烧3 h后,制备了锆英石/氮化硼陶瓷底模.结果表明:底模具有很好的抗热震性和对高钒钢的高温抗侵蚀性;线收缩率为2.5%(1400℃,3 h),...     

Machinability evaluation of machinable ceramics with fuzzy theory

The property parameters and machining output parameters were selected for machinability evaluation of machinable ceramics. Based on fuzzy evaluation theory, two-stage fuzzy evaluation approach was applied to consider these parameters. Two-stage fuzzy comprehensive evaluation model was proposed to evaluate machinability of machinable ceramic materials. Ce-ZrO2/CePO4 composites were fabricated and machined for evaluation of machinable ceramics. Material removal rates and specific normal grinding forces were measured. The parameters concerned with machinability were selected as alternative set. Five grades were chosen for the machinability evaluation of machnable ceramics. Machinability grades of machinable ceramics were determined through fuzzy operation. Ductile marks are observed on Ce-ZrO2/CePO4 machined surface. Five prepared Ce-ZrO2/CePO4 composites are classified as three machinability grades according to the fuzzy comprehensive evaluation results. The machinability grades of Ce-ZrO2/CePO4 composites are concerned with CePO4 content.     

CaO-MgO-Al2O3-SiO2-F系可切削微晶玻璃的晶化机理研究

在CaO MgO Al2 O3 SiO2 F系可切削微晶玻璃体系中 ,本研究分析了K2 O和ZrO2 对玻璃析晶和显微结构的影响 ,探讨了晶化机理。K+ 促使云母相的生成和球晶的形成 ;晶化过程中 ,云母和顽辉石互为外延生长 ,使球晶中条状晶解离为片状晶。ZrO2 与F- 一起促使玻璃晶化后形成棒状云母晶粒 ,并具有晶粒长径比大、相互交错的显微结构     

镶嵌式小型十六极阵列质谱计分析器的研制

结合我国可机加工陶瓷材料及其精密加工技术现状,提出独具特色的小型十六极阵列质谱计分析器的镶嵌式结构。根据分析器电极排列几何精度与质量范围、分辨率之间关系,提出设计要求,给出镶嵌式分析器整体和关键部件的结构设计,以及关键部件的测量结果。分析器的体积和重量为15.4 cm3和50.3 g,质量范围和质量分辨率为50 amu和1 amu。最后,展望了镶嵌式小型十六极阵列质谱计的应用前景。     

氟金云母陶瓷车削参数对刀具磨损的影响

对氟金云母可加工陶瓷进行车削加工试验,分析了切削中的刀具磨损特性,讨论了影响刀具磨损率的因素。以单因素实验法分别考察了刀具材料、冷却条件、切削深度、进给速度等对刀具磨损的影响规律。结果表明:刀具磨损过程可划分为三个阶段,自来水冷却可降低刀具磨损率,高速钢刀具不能满足加工需要,陶瓷刀具相对较好;切削深度对刀具磨损率的影响曲线为一抛物线段,进给速度对刀具磨损的影响曲线为一余弦线段;车削氟金云母陶瓷对刀具磨损过程与切削金属相似。