Single depositions of 316L stainless steel in pulsed laser powder bed fusion were performed to understand the influence of energy density input strategy on melt pool morphology, microstructure and temperature fields. Depositions performed at equal energy inputs, but variable laser powers, produced keyhole mode depositions for laser powers ≥150 W and conduction mode depositions for laser powers below 150 W. The laser power combined to the laser exposure time was found to control the penetration depth, increasing from 50 μm to 300 μm as the laser exposure increases. An increase in laser exposure time was found to decrease the isotherm liquidus velocity, from 1.2 mm s⁻¹ to 0.2 mm s⁻¹. EBSD maps of deposition cross-sections highlighted the change in temperature gradients as the melt pool increased in depth during keyhole and conduction mode depositions. Strong sub-surface temperature gradients were found for keyhole mode with weak gradients above the surface. In conduction mode variation in the temperature gradient throughout the melt pool was less pronounced. The decrease in cooling rate as the exposure time is increased was highlighted in coarsening of the cell spacing produced by the solute redistribution during solidification, diverging between bottom and dome of the deposition melt pool.

为了了解能量密度输入策略对熔池形态，微观结构和温度场的影响，对脉冲激光粉末床熔合过程中的316L不锈钢进行了单次沉积。在能量输入相等但激光功率可变的情况下进行沉积，对于功率≥150W的激光，产生了小孔模式沉积，对于功率低于150 W的激光，产生了导电模式的沉积。发现激光功率与激光曝光时间相结合可以控制穿透深度，随着激光曝光量的增加，从50μm增加到300μm。发现增加激光曝光时间会使等温线液相线速度从1.2 mm s ^-1降低到0.2 mm s ^-1。沉积截面的EBSD图突出显示了在键孔和传导模式沉积过程中，随着熔池深度的增加，温度梯度的变化。对于锁孔模式，发现表面下的温度梯度较强，而表面上方的梯度较弱。在传导模式下，整个熔池中温度梯度的变化不太明显。随着固化时间的增加，冷却速率的降低随着暴露时间的增加而突出，这是由于凝固过程中溶质的重新分布所产生的晶胞间距变粗，沉积熔池的底部和穹顶之间有分歧。