IMPROVEMENTS RELATING TO ADDITIVE LAYER MANUFACTURE USING CHARGED PARTICLE BEAMS

A method of charge mitigation in additive layer manufacturing is provided, which uses a charged particle beam (103) to fuse metal powder (122) within a metal powder bed (123) to form a product layer-by-layer, the method comprising using a charged particle beam optical system to form a charged particle beam, to steer the charged particle beam to be incident on a powder bed of metal powder and to scan over the powder bed to fuse powder into a desired layer shape. While steering the charged particle beam, the method comprises using a neutralising particle source (160) to generate neutralising particles of an opposite charge to the charged particles in the vicinity of the charged particle beam such that the neutralising particles are attracted to the charged particles of powder in the powder bed. An additive layer manufacturing apparatus (100) is also provided. 提供了添加层制造中的电荷迁移的方法，其使用带电粒子束(103)来熔融金属粉末床(123)内的金属粉末(122)以逐层形成产品，该方法包括使用带电粒子束光学系统来形成带电粒子束，操控带电粒子束入射在金属粉末的粉末床上并且扫描过粉末床以将粉末熔融成期望的层形状。在操控带电粒子束的同时，该方法包括使用中和粒子源(