3D金屬粉末列印之粉末燒結參數研究

3D metal powder printing sintering parameter studies

林久瑋(Jiou-Wei Lin)

指導教授 ： 許坤明

國立虎尾科技大學/工程學院/機械與電腦輔助工程系碩士班/碩士(2017年)

摘要

目前產業上一體化形成的製程競爭非常激烈，隨著3D列印技術不斷發展，其技術也逐年增長，產值也越來越高，目前國內現階段較常看到的3D列印以PLA或ABS等高分子線材熔融後堆疊成型為主，因價格低廉及操作技術簡單，在一般學校多以購入此種機台做教學。至於金屬的3D列印需要在密閉空間中通入保護氣體，以雷射加工方式燒結堆疊成型，使用材料為金屬粉末，該技術雖可製作複雜的零件，但因價格昂貴因此國內少有相關技術研發。
本論文主要在研究3D金屬粉末燒結製程技術，將不同種類的金屬粉末混合並進行雷射燒結實驗，確定粉末燒結的可行性，其後以不同的雷射功率、掃描速度、頻率及路徑間距等參數，在不同實驗條件下進行粉末燒結實驗，並利用光學顯微鏡及維氏硬度試驗機針對燒結製品進行驗證，以田口法找出最佳製程參數組合。
經由研究結果其結論歸納為以下幾點：
1.本研究設計製作粉末混合機構，並利用此機構混合銅粉及錫粉，含量比為18：1。
2.若掃描速率高於30mm/s以上，粉末會因溫度不足有明顯飛濺現象不利於燒結成型，對於之後所做的孔隙率及硬度分析實驗會有較大的影響。
3.由田口分析可知孔隙最佳製成參數組合，可知最佳孔隙為4.712%，其雷射功率80%、掃描速度7mm/s、頻率30kHz、路徑間距為0.05mm。
4.由田口分析可知維氏硬度最佳製成參數組合，可知最佳孔隙為134.423HV，其雷射功率100%、掃描速度7mm/s、頻率33kHz、路徑間距為0.07mm。

關鍵字

雷射燒結 ； 金屬粉末 ； 田口法

並列摘要

In the current industry, integrated manufacturing is highly competitive. As 3D printing continue to develop, the techniques and output value are also expending. In the present domestic market, 3D printing with PLA or ABS filament wires are the most common materials. Due to the low-cost and easy operation, the machine is often purchased by schools as a teaching tool. As for the metal 3D printing, it needs to insert protective gas in a closed off space, through laser sintering and stack-build to create an object with metal powder, although such techniques can produce complex parts, very few technical developments are found in the domestic market due to the high cost.
The purpose of this study is to focus on the research of 3D metal powder sintering techniques and process. Through laser sintering experiments with different metal powder mixtures to confirm possible powder sintering, then use different laser power, scanning speeds, frequencies and path spacing parameters to conduct powder sintering experiments under different experimental conditions. By using optical microscope and Vickers Hardness tester to verify sintering products and using Taguchi method to find out best parameter combinations.

The conclusions of the study are summarized as follow
1.In this study, the powder mixing mechanism was designed and used, the ratio of copper and tin powder for the mixing mechanism was 18: 1
2.If the scanning rate is higher than 30mm/s, the powder indicates insufficient temperature and shows a splash phenomenon which is not conducive to sintering. This will subsequently impact on the porosity and hardness analysis experiments.

3.Through Taguchi analysis, the best combine parameters for pore-space were found. The best pore-space is 4.712%, the laser power is 80%, and the scanning speed is 7mm/s, the frequency is 30k, and the path-space is 0.05mm.
4.Through Taguchi analysis, the best combine parameters for Vickers Hardness were found. The best pore-space is 134.423HV, the laser power is 100%, the scanning speed is 7mm/s, the frequency is 33K, and the path-space is 0.07mm.

並列關鍵字

laser sintering ； metal powder ； Taguchi method

參考文獻

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