**A Review of Spatter in Laser Powder Bed Fusion Additive Manufacturing: In Situ Detection, Generation, Effects, and Countermeasures**

**Zheng Li <sup>1</sup> , Hao Li <sup>1</sup> , Jie Yin 1,\*, Yan Li <sup>1</sup> , Zhenguo Nie <sup>2</sup> , Xiangyou Li <sup>3</sup> , Deyong You <sup>4</sup> , Kai Guan <sup>5</sup> , Wei Duan <sup>6</sup> , Longchao Cao <sup>7</sup> , Dengzhi Wang <sup>3</sup> , Linda Ke <sup>8</sup> , Yang Liu <sup>9</sup> , Ping Zhao <sup>10</sup> , Lin Wang <sup>11</sup>, Kunpeng Zhu <sup>6</sup> , Zhengwen Zhang <sup>12</sup>, Liang Gao <sup>13</sup> and Liang Hao <sup>1</sup>**


**Abstract:** Spatter is an inherent, unpreventable, and undesired phenomenon in laser powder bed fusion (L-PBF) additive manufacturing. Spatter behavior has an intrinsic correlation with the forming quality in L-PBF because it leads to metallurgical defects and the degradation of mechanical properties. This impact becomes more severe in the fabrication of large-sized parts during the multi-laser L-PBF process. Therefore, investigations of spatter generation and countermeasures have become more urgent. Although much research has provided insights into the melt pool, microstructure, and mechanical property, reviews of spatter in L-PBF are still limited. This work reviews the literature on the in situ detection, generation, effects, and countermeasures of spatter in L-PBF. It is expected to pave the way towards a novel generation of highly efficient and intelligent L-PBF systems.

**Keywords:** spatter; laser powder bed fusion; in situ detection; generation mechanism; detrimental effects; counter-measures; additive manufacturing
