3）對(duì)選區(qū)激光熔化鉭顯微組織及力學(xué)性能的影響。采用掃描電子顯微鏡和電子背散射衍射對(duì)選區(qū)激光熔化鉭的顯微組織進(jìn)行表征，并對(duì)其顯微硬度和拉伸性能進(jìn)行檢測(cè)。結(jié)果表明，選區(qū)激光熔化鉭顯微組織由明顯向上生長的柱狀晶構(gòu)成，雙層掃描后的鉭具有更細(xì)的晶粒尺寸。隨著輸入能量密度的提高，選區(qū)激光熔化鉭的強(qiáng)度、顯微硬度和塑性均具有明顯的上升趨勢(shì)。此外，雙層掃描工藝可進(jìn)一步提高材料密度，且在保留強(qiáng)度的基礎(chǔ)上，增強(qiáng)材料塑性。在能量密度為640 J/mm3（雙層掃描）時(shí)，金屬鉭性能最優(yōu)，顯微硬度、極限抗拉伸強(qiáng)度及延伸率分別為2307 MPa，527 MPa和11.4%。;The effects of single-layer and double-layer scanning strategies and energy density (246–640 J/mm3) on the microstructures and mechanical properties of Ta prepared by selective laser melting (SLM) were investigated. The microstructure of SLM-processed Ta was characterized by scanning electron microscope and electron backscatter diffractometer. The microhardness and tensile properties were also tested. Results show that the Ta microstructure is composed of columnar crystals with obviously upward growth trend and the Ta prepared by double-layer scanning has finer grain size. With increasing the input energy density, the strength, microhardness, and ductility of the as-built Ta are significantly improved. In addition, the double-layer scanning strategy can further improve the densification of Ta specimen, and even increases the ductility without strength loss. When the energy density is 640 J/mm3 (double-layer scanning), the as-built Ta exhibits optimal properties: the microhardness, ultimate tensile strength, and elongation are 2307 MPa, 527 MPa, and 11.4%, respectively."/>