TiO_2对ZrO_2－NiCr金属陶瓷烧结特性和相稳定性的影响

本文研究了ＴｉＯ２掺入对ＣａＯ稳定ＺｒＯ２（简称ＣａＳＺ－ＮｉＣｒ）金属陶瓷烧结特性的影响，测定了ＣａＳＺ－ＮｉＣｒ－ＴｉＯ２金属陶瓷烧结样品的密度和显微硬度，结果表明，ＴｉＯ２的掺入能提高ＣａＳＺ－ＮＩＣｒ金属陶瓷的烧结密度和显微硬度，对ＣａＳＺ－ＮｉＣｒ金属陶瓷有助烧结作用．金相观察表明，ＴｉＯ３的掺入改变了ＮｉＣｒ相在金属陶瓷中的形貌，说明了ＮｉＣｒ与ＣａＳＺ的浸润性有一定的改善．ＸＲＤ和ＥＰＭＡ分析结果显示，ＴｉＯ２偏聚在ＮｉＣｒ金属相中，不影响ＣａＳＺ的稳定性．     

适于等离子喷涂的PSZ粉末的性能研究

研究了用共沉淀法制备的，适于等离子喷涂的８ｗｔ％Ｙ２Ｏ３－ＺｒＯ２部分稳定氧化锆粉末的性能。用日本Ｄ／ＭＡＸ－１ＡＸＸ－射线衍射仪（ＸＲＤ）研究了粉末的相组成；用日本ＳＸ－４０扫描电镜（ＳＥＭ）观察了颗粒形貌和团聚状况；用日本Ｈ－６００分析电镜（ＳＴＥＭ）确定晶粒大小和化学组成；用英国激光粒度分布测定仪测定了粉末的粒度分布；用日本粉体综合测定仪测定了粉末的流动性。并探讨了所制粉末性能与制备工艺的关系。     

Ti-Al-B系统自燃烧合成TiB_2的研究

本文较系统地研究了Ti、B以及Al粉末混合自燃烧合成TiB_2/Al体系,探讨了在Al基中TiB_2粒子的形成机理,讨论了Al、B元素、合成温度以及含H体系对Ti-Al-B系反应产物相组成的影响。结果表明,Ti-Al-B系燃烧合成TiB_2的最佳温度为≥900℃;合成产物的相组成主要取决于Ti和B在反应物中的比例,并且受处理工艺的影响;Al和H的存在可以延缓TiB_2合成反应;TiB_2粒子的平均粒度主要取决于Al在反应物中的比例,一般地,TiB_2粒子的大小在0.5～5μm的范围内。     

AN INVSTIGATION ON THE STRENGTHENED PLATINUM ALLOY ADDED MINIMAL Zr AND Y

The effect of adding minimal Zr and Y onstrengthened platinum is studied in this paper. The results showthat strengthened effect by adding double elements Zr and Y ismore evident than that by adding single element Zr.     

PHASE TRANSFORMATION OF ZrO_2-8%Y_2O_3 DURING ANNEALING AT HIGH TEMPERATURE

In this study,coatings of zirconia alloyed with8wt% yttria were prepared by plasma spraying.A comprehensivesequence of annealing experiments comprising time from 1 to 100hours at temperatures between 1100 and 1500℃ were carried out.It is shown that the T′phase in coatings decomposes into low yttriatetragonal phase(T_1′)and high yttria tetragonal phase(T_2′)following high temperature annealing.The content of YO_(1.5)in T_1′decreases with the increasement of annealing time.Both T_1′andT_2′phases are also “non-transformable”tetragonal phases.Andfurther annealing causes a cubic phase (C) to precipitate fromT_2′.The increasement of C phase is accompanied by the decrease-ment of T_2′phase.The probable mechanism of T′→T_1′ T_2′phase transformation is of spinodal decomposition and that of T_2′→C is of precipitation.