流延法制备ZrO2/不锈钢功能梯度材料

采用流延法制备了ZrO2/316L不锈钢功能梯度材料,利用成分分布函数设计梯度层厚度来减小各层间的残余应力,通过改变黏合剂添加量得到各梯度层中ZrO2的体积分数(φ)和黏合剂与混合粉体积比(M)的关系:M=1.029φ 1.652,并研究了烧结工艺对材料组织形貌的影响.结果表明:在真空无压条件下,1 350 ℃烧结可得到成分呈梯度变化,各梯度层界面结合良好的ZrO2/316L功能梯度材料.     

流延法制备对称型ZrO2/不锈钢功能梯度材料

采用流延法制备了成分梯度为10%(体积含量,下同)的对称型ZrO2/不锈钢功能梯度材料,利用成分分布函数和经典层合板理论对成分和残余热应力的分布进行了设计分析,观察了其微观形貌,并对截面的显微硬度进行了表征.结果表明:采用流延法制备的对称型ZrO2/不锈钢功能梯度材料成分过渡良好,梯度层界面结合紧密,与对称型层状ZrO2/不锈钢复合材料相比,最大残余热应力减小,热应力缓和效果明显.     

一种新型的水系流延工艺制备中温SOFC电解质YSZ薄膜

采用-种新型的水系流延工艺制备中温SOFC电解质YSZ薄膜浆料.研究了同时添加粘结剂和分散剂的浆料的流变性,不同含量粘结剂对这种浆料粘度的影响,该工艺对流延片的干燥特性、生坯密度和坯片烧结性能的影响.实验结果表明:该浆料的假塑性程度和浆料的粘度随着B-1070的含量增加而减小;发现采用该工艺的干燥时间明显缩短;YSZ坯片的生坯密度大大提高,相对密度达到55.3%.所得流延素坯在1450℃保温2小时烧结能获得相对密度达98.5%的YSZ电解质薄膜.     

CaO-B2O3-SiO2玻璃陶瓷系生料带流延工艺研究

采用正交实验研究固含量、粘结剂和增塑剂对CBS(CaO-B2O3-SiO2)玻璃体系浆料粘度、生坯性能影响.利用STATISTICA 6.0分析表明:固含量、PVB和DBP的交互作用分别对浆料粘度和生料带的可揭膜程度影响最大,单因素及其交互作用对生坯密度均无显著影响.固含量50wt%.相对CBS玻璃粉料添加2wt%蓖麻油,7.5wt%PVB、4.5wt?P时,制备的浆料粘度为2.1 Pa.s.较适合流延,生坯体积密度达到1.6g.cm-3,且生料带较易从流延机上剥离.875℃低温烧结试样,在100Hz微波频率下测试,介电常数为6.56,介电损耗1.57×10-3.     

PVB对Ca-Ba-Mg-Al-B-Si-O玻璃/Al_2O_3材料性能的影响

以Ca-Ba-Mg-Al-B-Si-O玻璃和Al_2O_3为原料,加入流延剂后流延成型生瓷带,采用低温烧结法制备了玻璃/Al_2O_3系介电陶瓷材料。设计添加PVB粘结剂与KH-570型硅烷偶联剂协同优化流延工艺,重点研究了PVB粘结剂对浆料特性、生瓷带性能以及生坯烧结性能的影响。随着PVB相对分子量降低,浆料固含量增加,生瓷带体积密度增加,拉伸强度与断裂伸长率逐渐降低。PVB粘结剂中的PVB、PVA、PVAc基团在溶剂中溶解,产生一定粘度,使玻璃/Al_2O_3浆料具备合适流延的粘度。添加PVB-5s的玻璃/Al_2O_3浆料的固含量为67 wt%,相应生瓷带体积密度为1.92 g·cm~(-3),拉伸强度为1.42MPa,生瓷带表面光滑致密,生坯于850℃烧结良好,烧结体微观结构致密,介电性能优良,因此该体系材料比较适合用作低温共烧陶瓷材料。     

细晶氧化铝陶瓷基板的流延成型和显微结构控制研究

采用砂磨工艺获得了亚微米氧化铝复合粉体,用于制备微晶氧化铝陶瓷基板,研究了浆料组成对浆料流变学性质、生坯密度、生坯应力-应变行为的影响,以及烧结制度对平均晶粒尺寸和基板抗弯强度的影响。结果表明,固相含量、R值(增塑剂和黏结剂的质量比)和分散剂用量等关键因素决定了流延浆料的流变学性质。R值增大导致生坯强度和密度降低,提高固相含量有利于增加最大可流延厚度,优化工艺条件下可制备0.16～1.20 mm的坯片。当烧结温度为1 550℃、升温速率为2.5℃/min、保温时间为60 min时,制备的陶瓷基板平均晶粒尺寸为1.1μm左右,晶粒尺寸分布均匀,抗弯强度达到(440±25) MPa。     

低温共烧CBS基片的流延成型及其性能的研究

选用4种分散剂(三乙醇胺,磷酸三丁酯,蓖麻油和三油酸甘油酯),通过对分散剂的用量、固含量对浆料流变性能、流延生坯及烧结体性能的研究。分析了分散剂及固含量对流延浆料及陶瓷性能的影响。实验结果表明:以磷酸三丁酯为分散剂,当浆料的固含量为55%时,制备的料浆不仅分散性好而且稳定。流延所得烧结体介电常数为6.47、介质损耗为1.1×10-3。烧结后的样品中主要包含CaSiO3、CaB2O4和SiO2晶相。达到了LTCC材料的要求。     

BaTiO3瓷粉水基流延成型的研究

本文以BaTiO3瓷粉为原料，聚丙烯酸酯类水性粘合剂为载体，通过水基流延成型成功制备了20-25μm的电子陶瓷素坯膜；研究了水性粘合剂对浆料的流变性、流延素坯膜的力学性能及微观结构的影响。结果表明，水性粘合剂的用量为10％时，流延素坯膜的综合性能较好．BaTiO3在粘合剂中分散均匀。     

铌酸钾钠无铅压电陶瓷水系流延浆料的工艺研究

模版晶粒生长技术制备织构化铌酸钾钠无铅压电陶瓷是提高其压电性能的重要途径,为了获得较高的织构度,水系流延浆料的制备是关键技术.本研究以固相法合成的铌酸钾钠粉体和片状Nb2O5模板晶粒为固含量,以去离子水为溶剂,研究不同含量的分散剂、粘结剂和增塑剂对流延浆料性能的影响.研究结果表明,当粉体固含量为55wt％,分散剂PVP含量为5.5wt％,粘结剂苯丙乳液含量13.5wt％,增塑剂丙三醇含量为5.5wt％时,制备的流延浆料粘度适中,流延后可制得表面光滑、质地均匀、塑性较好、可任意卷曲的流延膜片.     

AlN基片流延浆料粘度的研究

本文研究了影响AIN流延浆料粘度的主要因素,结果表明,环境温度或溶剂比例的增加,浆料的粘度值下降,而较细的粒度和增塑剂的减少则使粘度上升。本文还指出了严格控制各影响因素以实现稳定流延工艺的必要性。     

Investigation of stainless steel 316L/zirconia joint part fabricated by powder injection molding

The joint part of stainless steel 316L (SUS316L)/zirconia was investigated. The specimens were fabricated using the powder injection molding (PIM) with insert-injection molding. SUS316L, zirconia, and a mixture of SUS316L and zirconia were used as bonding materials. The processing conditions for PIM were developed and optimized to avoid defects in the final sintered part. The bonded parts of SUS316L/mixed layer and zirconia/mixed layer were fabricated without joint failure. However, warpage and contamination existed due to the different sintering behavior and remaining binders. To reduce the warpage, the solids loading of SUS316L were changed to 44 and 40 vol. %. The warpage was decreased by reducing the shrinkage difference between the SUS316L and mixed layer. The contamination was also reduced by increasing the powder bedding in the debinding and sintering process. The microstructures and chemical compositions were confirmed by a scanning electron microscope (SEM) and an energy dispersive X-ray spectroscope (EDS). Migration of the main components was observed at the interface and the main components were presented together at the whole part interface and interface between 2 materials in the mixed layer. It was confirmed that the joining was done with bonding of the same materials in each layer and diffusion bonding.     

8%Y2O3-ZrO2水基料浆的流变性质研究

详细研究了固含量、球磨时间、分散剂用量和pH值对8％摩尔分数Y2O3稳定ZrO2水基料浆流变性质的影响。结果表明：料浆均表现出剪切变稀行为，且为假塑性流体。确定了最佳实验参数，当pH=10，分散剂用量为2％体积分数，球磨24h的ZrO2水基料浆，稳定性好，适合于成型薄片ZrO2固体电解质材料，并最终制备出体积分数为56％，适合浇注的ZrO2陶瓷料浆。     

Lubrication performance of diamond-like carbon and fluorinated diamond-like carbon coatings for intravascular guidewires

Diamond-like carbon (DLC) and fluorinated DLC (F-DLC) films were deposited on SUS316L guidewires using radio frequency (RF) plasma enhanced chemical vapor deposition (CVD), and the lubrication performance of DLC- or F-DLC-coated guidewires was then evaluated under in vitro conditions using a novel friction simulator developed for this study. Scanning electron microscopy (SEM) demonstrated that DLC or F-DLC film completely coated the specimens (SUS316L guidewires) and that polishing scars were substantially reduced. In the torturous vessel model, DLC- or F-DLC-coated guidewires exhibited significantly improved lubrication performance (by approximately 30% over that of uncoated wires). DLC and F-DLC films are thus promising candidates for lubricious coating of intravascular guidewires.     

氧化锆陶瓷注凝成型研究

本文对ZrO2注凝成型工艺中分散剂、固相体积含量对浆料流变性的影响进行了研究.研究表明分散剂的加入可以使浆料的Zeta电位值提高近40mv,浆料粘度降低;随固相体积含量增加,浆料粘度增加,但使浆料粘度降至最低所需分散剂的量减少.     

柠檬酸酸解反应釜腐蚀原因分析及其解决

针对柠檬酸钙酸解生成柠檬酸时反应釜腐蚀严重的现象,通过设备使用、工艺控制等方面的检测和分析,找出了设备腐蚀的原因.采用SUS 31803双相不锈钢代替原SUS316L不镑钢,在反应釜底部加硫酸,并分散加浓硫酸的位置.设备使用1a后,经检查设备腐蚀量,符合设计要求,解决了设备腐蚀问题,保证了生产的连续性,同时提高了碳酸钙...     

Deposition of DLC film with adhesive W-DLC layer on stainless steel and its tribological properties

Tribological properties of a diamond-like carbon (DLC) coating with an adhesive tungsten-containing DLC (W-DLC) layer were investigated. The coatings were deposited onto AISI316L steel substrates and Si wafers using plasma enhanced chemical vapor deposition and tungsten co-sputtering of the metal target. Methane and argon gases were used as the precursor of the coatings. In this study, three types of coatings were evaluated: DLC/W-DLC on AISI316L (DLC-1), DLC/W-DLC on Si wafer (DLC-2), and DLC on Si wafer (DLC-3). The structural characterizations were performed by transmission electron microscopy and tapping mode atomic force microscopy. At the boundary between the W-DLC layer and the AISI316L substrate, microscopic decohesion or delamination was not observed. The surface roughness of the DLC-1 coating was greater than that of the DLC-2 coating. This feature was derived from the surface roughness of the initial surface of the AISI316L substrate. Friction tests were performed using a rotation-type ball-on-flat configuration tribometer. The observed friction of the DLC-1 coating was unstable compared with the DLC-2 or DLC-3 coatings. This was due to wear debris which had risen to the friction surface resulting in unstable friction on the DLC-1 coating. During the friction studies, the top DLC layer was removed from the adhesive W-DLC layer because the adhesive strength at this part was not enough. In order to achieve the low and stable friction of the DLC coating with the W-DLC layer on AISI316L, it is necessary to improve the smoothness of the surface and the adhesion between the DLC coating and the W-DLC layer.     

超临界C02干燥法工艺条件对氧化锆气凝胶结构性质的影响

以无机盐ZrOCl2·8H2O为原料,采用溶胶-凝胶过程结合超临界CO2干燥法制备了ZrO2气凝胶.采用BET、TG/DTA、XRD、TEM以及SEM等手段对样品进行了表征分析.考察了超临界CO2干燥过程中,操作压力、操作温度、CO2流率及干燥时间等工艺条件对样品比表面积、孔性质等的影响.结果表明利用本方法制备的ZrO...     

溶胶-凝胶法在SiC纤维表面制备ZrO2界面层的研究

采用溶胶凝胶法(sol-gel)在SiC纤维表面制备氧化锆(ZrO2)界面层,考察了前驱体溶胶和烧结温度对界面层的影响。采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)等测试手段对ZrO2界面层的晶体结构和表观形貌进行了分析。结果表明:当烧结温度为1 000℃,Zr4+金属离子浓度为1.0 mol/L,聚乙烯醇(polyvinylalcohol,PVA)质量分数为30%时,能够制备出完整致密的ZrO2界面层。