The invention provides a support-free forming method for
laser powder bed melting, and relates to the technical field of
metal additive manufacturing, and the horizontal support-free forming method for
laser powder bed melting comprises the following steps: S1, printing a first-layer support-free overhanging surface by using an out-of-focus
laser beam, so that a first-layer
metal powder is in a
sintering state, and a first-layer
sintering layer is formed; s2, printing a predetermined number of
layers of support-free overhanging surfaces layer by layer by using an out-of-focus laser beam, melting each new printing layer, remelting the previous printing layer, and avoiding remelting to the lower surface of the first
sintering layer; and S3, after printing of the support-free overhanging surface with the preset number of
layers is completed, subsequent layer printing is conducted. The first sintering layer is printed by using the out-of-focus laser beam, so that a supporting foundation is provided for a subsequent overhanging structure, and the problem of collapse of the first layer is avoided. Fusion and combination of each new printing layer and the previous printing layer are controlled, remelting to the lower surface of the first layer is avoided, the upper surface and the lower surface which are not supported are smooth, and powder adhesion is avoided.