采用激光选区熔化（SLM）技术制备TC4钛合金，研究了激光体能量密度对合金表面质量和致密化行为的影响。结果表明：随着激光体能量密度由33 J·mm^-3增加到80 J·mm^-3，合金表面粗糙度减小，表面质量提高，表面球化现象明显改善；随着激光体能量密度的增大，合金内部孔洞减少，相对密度由90.5%增大到99.3%，但过高的激光体能量密度下熔体的过度流动影响成形件的尺寸精度及性能；制备该合金的最佳参数为激光体能量密度66 J·mm^-3，即激光功率250 W，扫描速度500 mm·s^-1，此时合金的表面质量和致密性均较好。

The TC4 titanium alloy was prepared by selective laser melted (SLM) technique, and the effect of laser bulk energy density on surface quality and densification behavior of the alloy was studied. The results show that when the laser bulk energy density increased from 33 J·mm^-3 to 80 J·mm^-3), the surface roughness of the alloy decreased, indicating the surface quality was improved; the surface balling effect was improved significantly. With the increase of the laser bulk energy density, the amount of voids inside the alloy decreased and the relative density increased from 90.5% to 99.3%; but excessive flow of the melt at an over high laser bulk energy density affected the dimensional accuracy and properties of the formed parts. The optimum parameter for preparing the alloy was the laser bulk energy density of laser 66 J·mm^-3, namely the laser effect of 250 W and scanning velocity of 500 mm·s^-1, and the alloy had good surface quality and densification.