- 學位論文
6-4鈦合金α-case結構分析
Analysis of Mechanical Variation on Ti-6Al-4V with α-case phase
摘要
本文利用掃描式電子顯微鏡 ( SEM )、場發射掃描式電子顯微鏡 ( SEM-EDS )、X光繞射分析儀 ( XRD )等方法，觀察6-4鈦合金α-case結構分析顯微結構，研究結果如下： 經由SEM圖觀察，其顯微結構分為三種不同型態呈現，在800℃、840℃時效，外部顯微結構為晶粒狀α-case，以及α-case邊界有許多細小β鈦殘留，內部顯微結構為α+β鈦;在920℃、960℃時效，變態點以下時效，外部顯微結構為晶粒狀α-case，有明顯之擴散層深入，大致上由外到內可分為α-case層、氧擴散層、原始層;在1040℃、1080℃時效，外部顯微結構為板狀α-case，且根據晶粒的晶界會有不均勻之分布狀況。經由顯微組織觀察，發現其α-case層會有孔洞及微裂紋產生，孔洞在低溫時，為垂直成長，時間越長垂直成長變為水平成長，溫度越高，使孔洞會呈水平且聚集成長。 亦由成分分析及顯微結構觀察出含氧量由外而內的變化，初步判斷外層為一層TiO2氧化層，接著為α-case氧化層，往內部即有氧擴散層、原始結構層。 α-case的深度隨著溫度變化而改變，深度量測後可觀察出，時效的溫度影響α-case的深度較固溶溫度來的高。
並列摘要
This text utilizes a scanning electron microscope (SEM), field emission scanning electron microscope (SEM-EDS), X-ray diffraction analyzer (XRD) method, observed 6-4 titaniumα-case structure analysis of the microstructure. The results of study are as follows: Through the observation of SEM images, the microstructure is divided into three different types presented in 800 ℃ and 840 ℃ aging, many of the small β titanium residue external microstructure of the grain-like α-case, as well as alpha-case boundary, imicrostructure for the α + β titanium; in 920℃ and 960 ℃ aging, aging following a perverted point external microstructure of the grain-like α-case, the diffusion layer depth, generally from outside to inside can be divided into α-case layer, the oxygen diffusion layer,the original layer ; in 1040 ℃, 1080 ℃ aging, external microstructure plate of α-case, and according to the grain boundaries will have uneven distribution of position. Through microstructure observation, found that the α-case layer will be holes and micro-cracks, holes for the vertical growth at low temperature, time, the longer the vertical growth into the level of growth, the higher the temperature, so that the holes horizontal and gatheredgrowth. Also the composition and microstructure observation of the oxygen content changes from outside to inside, the initial judgment the outer layer of TiO2 oxide layer, followed by oxidation of α-case layer, the aerobic diffusion layer to the internal, the original structural layer. The α-case depth with the temperature changing, depth measurements can be observed ,the aging temperature effect of the α-case depth is higher than the solution temperature.