Cross-scale coordination: Laser-based additive manufacturing has the potential to revolutionize how components are designed. Gu et al. suggest moving away from a strategy that designs and builds components in a serial manner for a more wholistic method of optimization for metal parts. The authors summarize several key developments in laser powder bed fusion and directed energy deposition and outline a number of issues that still need to be overcome. A more integrated approach will help to reduce the number of steps required for fabrication and expand the types of structures available for end-use components. Science , abg1487, this issue p. eabg1487
Three types of scanning strategies, including the chessboard scanning strategy, the zigzag scanning strategy and the remelting scanning strategy, were conducted to study the effects of scanning strategies on surface morphology, microstructure, mechanical properties and the grain orientation of selective laser melted pure tungsten. The results showed that the pores and cracks were main defects in SLM-processed tungsten parts. The pores could be eliminated using the remelting scanning strategy. However, the cracks seemed to be inevitable regardless of the applied scanning strategies. The microstructures of SLM-processed tungsten were columnar grains and showed strong epitaxial growth along the building direction. A compressive strength of 923 MPa with an elongation of 7.7% was obtained when the zigzag scanning strategy was applied, which was the highest among the three scanning strategies. By changing the scanning strategies, the texture of SLM-processed tungsten in the direction of processing could be changed.