本研究之主要目的是以AZ31鎂合金作為基材，以WS_2無機奈米管為強化相，利用重力鑄造及機械攪拌製備鎂基複合材，WS_2之添加量為0.1 wt. %及0.2 wt. %，以水刀切割成試棒後進行T4固溶處理，再分別以90°及120°之等徑轉角擠壓(ECAP)模具進行擠製，探討不同轉角及道次對於AZ31/WS_2 INT複合材之微觀結構及機械性質差異。
從實驗結果中可以發現添加WS_2INT能夠透過晶粒細化有效的提升材料之降伏強度及延展性，透過T4熱處理能使得β-Mg_17 Al_12相溶解於機材中並析出鋁錳相，該相的析出有助於提升材料之延展性，而透過多道次ECAP擠製能使材料產生動態再結晶使晶粒大小更細並提升其延展性及拉伸強度，但由於90度ECAP所造成之應變過大使得材料無法保有良好的成形性。結合XRD、EBSD分析及拉伸實驗結果得知材料在經過不同道次ECAP後將呈現不同之結晶取向，在經過2道次ECAP後材料之結晶取向傾向於[1 ̅21 ̅0]方向使得最強之降伏強度達到164.3 MPa，而經過4道次ECAP後材料之結晶取向傾向於[0001]方向使得最強之降伏強度僅有114.1 MPa，該現象的主因為當拉伸方向與六方結構之c軸夾角不同時會影響主要的滑動模式。

The main purpose of this study is to use AZ31 magnesium alloy as matrix and use WS_2-INT as the strengthening phase to produce Magnesium-based composites. After T4 heat treatment, materials will be extruded with 90° and 120° ECAP dies. Disscusions of effects about different angle and pass of ECAP will be included in this study.
From the experimental results, it can be found that adding additional WS_2-INT in the matrix can effectively enhance the material's strength and ductility through grain refinement. Through T4 heat treatment, the β-Mg_17 Al_12 phase can be dissolved in the material and aluminum precipitates. The precipitation of this phase increase the ductility of the material. The multi-pass ECAP extrusion enables dynamic recrystallization of the material to refine the grain size and increase its ductility and tensile strength. However, due to the strain caused by the 90 degree ECAP is too large, the material cannot maintain good formability. Combined with XRD, EBSD analysis and tensile test results, the material shows different crystal orientations after different passes of ECAP. After two passes of ECAP, the crystal orientation of the material tends to [1 ̅21 ̅0] direction which makes the strongest yielding strength reach 164.3 MPa , and after four passes of ECAP, the crystal orientation of the material tends towards [0001] which which makes the strongest yielding strength only 114.1 MPa. The phenomenon of different crystal orientation is the main cause of the material with 4 passes of ECAP being inferior to the material of 2 passes ECAP.

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