為了達到利用氣體霧化方式來製作出具高真圓度的球形粉體，降低具生物相容性Ti42Zr40Ta3Si15的液相溫度是必須的，所以鈦合金低液相溫度的設計理念是傾向該合金成份是接近於共晶點。一系列的Ti-Zr-Ta-Si-Sn-Co合金系統，將利用熔體紡絲技術來製作出薄帶，並以差示掃描量熱來探究熱性質和X光繞射儀來鑑定非晶質狀態，而由差示掃描量熱的結果顯示，將以適當的Co和Sn元素含量來取代該合金組成中的Zr和Si，可大幅降低從1728 K的Ti42Zr40Ta3Si15液相溫度轉變成1200 K，同時該合金成份的玻璃形成能力也向上提升。依據四種不同液相溫度的合金成份，利用氣體霧化技術來製作出具金屬玻璃結構的粉體，其結果顯示，較低液相溫度的合金成份，容易經氣體霧化技術後，得到球形的金屬玻璃粉體。同樣的在雷射再燒熔測試，在適當燒熔參數下，使用部分結晶的Ti42Zr35Ta3Si5Sn2.5Co12.5進行SLM，可得到連續全非晶的平面顯微結構，這表示該合金成份與雷射參數可進一步進行得到層與層堆疊的非晶構造。因此Ti42Zr35Ta3Si5Sn2.5Co12.5相信這有潛力的合金系統，可以製作出具高真圓度的粉體來運用於SLM;In order to reduce the liquidus temperature of the bio-compatible Ti42Zr40Ta3Si15 alloy for fabrication the spherical powder by gas-atomization process, the concept of lower liquidus temperature tendency near eutectic alloy composition was applied to design the Ti-based alloy with lower liquidus temperature. A series of Ti-Zr-Ta-Si-Sn-Co alloy ribbons were prepared by melt-spinning for evaluating their thermal properties and amorphous state by using differential scanning calorimeter (DSC) and X-ray diffraction analysis (XRD), respectively. The DSC results show that the liquidus temperature of Ti42Zr40Ta3Si15 alloy can be dramatically decreased by adding suitable amount of Co and Sn to substitute Zr and Si contents, liquidus temperature decreases from 1728 K to 1200 K. Meanwhile, the glass forming ability is also significantly improved. Accordingly, three alloy compositions with different liquidus temperatures were selected for fabricating the metallic glass powders by gas- atomization. The results reveal that the lower liquidus temperature of the alloy has, the more tendency to form the spherical metallic glass powder by gas-atomization process. In parallel, the results of pulse laser re-melting test on the partially crystallized Ti42Zr35Ta3Si5Sn2.5Co12.5 alloy powder shows that a continuous fully amorphous alloy layer can be formed under proper laser re-melting condition. This implies that the Ti42Zr35Ta3Si5Sn2.5Co12.5 alloys which contain major microstructure of amorphous phase also can be formed a continuous fully amorphous alloy layer by laser re-melting. Therefore, Ti42Zr35Ta3Si5Sn2.5Co12.5 alloys are believed to be the promising alloy system and can be fabricated into spherical metallic glass powders for the application of additive manufacturing by selective laser melting method.
