An additive manufacturing apparatus includes a platform, a dispenser to deliver a plurality of successive layers of feed material on the platform, a light source to generate one or more light beams, a first galvo mirror scanner positioned to direct a first light beam onto a topmost layer of the plurality of successive layers, a second galvo mirror scanner positioned to direct a second light beam onto the topmost layer of the plurality of successive layers, and a controller configured to cause the first galvo mirror scanner to direct the first light beam to pre-heat or heat-treat an area of the topmost layer and to cause the second galvo mirror scanner to direct the second light beam to fuse the area of the topmost layer.