Structure and properties of a cobalt-chromium-molybdenum alloy obtained by selective laser melting

Abstract

Cobalt-based heat-resistant alloys have unique properties that are used in corrosive environments and at high temperatures. The addition of chromium improves resistance to hot corrosion, while molybdenum improves corrosion resistance and strength. When machining a workpiece of a heat-resistant alloy, up to half of the material goes into chips and goes to processing. Modern trends in the development of additive technologies are aimed at saving material, introducing new materials and improving the physical and mechanical characteristics of the resulting products. Selective laser melting (SLM) is one of the additive methods for obtaining bulk metal products and is one of the most promising directions in the development of science and technology in recent years. This paper describes the porosity (the average value was 14 ± 5%), the structure and properties of alloy samples obtained by selective laser melting in the following modes: laser power - 100 W, scanning speed - 350 mm / s, thickness of the applied powder layer - 25 um, scanning step - 100 um, frequency of pulse-periodic laser action (modulations) - 2.5 kHz from a spherical powder of the CoCrMo alloy (66 wt% Co, 28 wt% Cr, 6 wt% Mo).