Powder recirculating additive manufacturing apparatus and method

A method of making a part by an additive manufacturing process, comprising the steps of:

• (a) supporting a solid build platform on top of a support surface that includes openings extending therethrough;
• (b) traversing a powder dispenser positioned above the support surface across the build platform, while dispensing powder from the powder dispenser, so as to deposit the powder over the build platform, wherein some of the powder dispensed falls through the openings in the support surface and into a collection hopper;
• (c) traversing the build platform with a scraper to scrape the deposited powder, so as to form a layer increment of powder, wherein excess powder is scraped from the solid build platform and through the openings in the support surface and into the collection hopper;
• (d) using a directed energy source to fuse the layer increment of powder in a pattern corresponding to a cross-sectional layer of the part;
• and
• (e) repeating in a cycle steps (b) through (d) to build up the part in a layer-by-layer fashion.