鈦金屬與氧化□、氧化鋯或氧化鈰的界面微觀結構分析

Abstract

本實驗利用熱壓方式產生緻密陶瓷試片與Ti金屬在1750℃進行界面反應，利用SEM、XRD、EPMA及TEM進行界面反應後之微觀結構分析。由實驗結果顯示，Y2O3熱壓試片與Ti液反應後，於Ti側固溶進O元素和些微Y元素，於陶瓷側固溶進Ti元素，由TEM顯示經由界面反應在Ti側與Y2O3側結構上並無改變。10 mol% Y2O3-90 mol%試片經由熱壓過後所加入10 mol% ZrO2完全溶入Y2O3形成固溶體。經由界面反應後於Ti側面處為β-Ti，且於Ti側發現有Ti3O有序結構，此改變應加和加入ZrO2量有關。30 mo1% Y2O3-70 mol % ZrO2 粉末經由熱壓過後有cubic Y2O3和殘存monoclinic ZrO2兩相，殘存ZrO2對Ti液特具反應性導致界面變為相當粗糙，且由TEM分析結果得知於陶瓷側有Zr-Ti-Y-O化合物產生。ZrO2加入會促使陶模對鈦液抵抗性降低。3 mol% Y2O3 partially stabillzed試片和Ti反應後形成大範圍反應區，且產生足夠O促成TiO2化合物形成。CeO2與Ti界面反應後大量崩解進入Ti液之中，而且有大量圓形Ce-O化合物因冷卻時超出飽合溶解度於Ti晶界上析出。經由微觀結構分析，可知Y2O3較ZrO2和CeO2對Ti淮而言有較佳安定性。

Ceramic plates were made by hot pressing, and then reacted with Ti melt at 175℃. The main interfacial reaction between yttria and titanium was into thermal dissolution. The titanium near the interface of 90 mol % Y2O3-10mol% ZrO2 over titanium changed from α-Tito β-Ti, while the order structure Ti3O forming was mainly induced by the addition of ZrO2. The as-pressed 70 mol % Y2O3-30 mol % ZrO2 plate contained cubic Y2O3 and residual monoclinic ZrO2. Titanium not only preferred to reacting with residual ZrO2 causing rough iterface but also extracted ZrO2 from Y2O3 to form Zr-Ti-Y-O compound during the interfacial reaction. 3% Y2O3 partially stabilizer ZrO2 plate reacted with Ti forming a wide reaction zone and evolved enough oxygen to form TiO2 in chemical reaction zone during a long reaction time(1750 ℃ /14min). The microstructure of the interface between titanium and ceria displayed that ceria has been seriously disintegrated by titanium. In addition, many spherical Ce-O compound particles precipitted due to over-saturated at titanium grainboundaries during cooling. According to microstructure analyses, the yttria has a best resistance to the titanium than do the ZrO2 and CeO2.