Additive manufacturing of high entropy alloys: A practical review

Additive manufacturing of magnetic materials

Additive manufacturing promises a major transformation of the production of high economic value metallic materials, enabling innovative, geometrically complex designs with minimal material waste. The overarching challenge is to design alloys that are compatible with the unique additive processing conditions while maintaining material properties sufficient for the challenging environments encountered in energy, space, and nuclear applications. Here we describe a class of high strength, defect-resistant 3D printable superalloys containing approximately equal parts of Co and Ni along with Al, Cr, Ta and W that possess strengths in excess of 1.1 GPa in as-printed and post-processed forms and tensile ductilities of greater than 13% at room temperature. These alloys are amenable to crack-free 3D printing via electron beam melting (EBM) with preheat as well as selective laser melting (SLM) with limited preheat. Alloy design principles are described along with the structure and properties of EBM and SLM CoNi-base materials. Additive manufacturing promises a major transformation of the production of high economic value metallic materials. Here, the authors describe a new class of 3D printable superalloys that are amenable to crack-free 3D printing via electron beam melting as well as selective laser melting.

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A defect-resistant Co-Ni superalloy for 3D printing.

Selective laser melting of NiTi alloy with superior tensile property and shape memory effect

Single-phase high-entropy alloys – A critical update

Progress in additive manufacturing on new materials: A review

In-situ reaction of Ti-Si-C composite powder and formation mechanism of laser deposited Ti6Al4V/ (TiC+Ti3SiC2) system functionally graded material

The invention relates to a method of additive manufacturing components, in particular to a method used for improving residual compressive stress of a laser additive manufacturing component. The methodcomprises the steps that powder materials are sequentially subject to agglomeration on the face of a substrate to form multiple lamination pieces which are stacked layer by layer from bottom to top,and in the process, after every time one or multiple lamination pieces are formed, the steps from S10 to S30 are executed; S10, a light-proof protection film is pasted on the surfaces of the lamination pieces, and the surface of the protection film is coated with liquid to form a liquid thin film on the protection film; S20, a pulse laser beam is adopted to shoot the protection film to enable theinterior of the additive manufacturing component to generate the compressive stress; S30, the protection film is removed. Pressure peaks formed by impact waves generated by the technology exceed the yield strength of the lamination layer of the lamination pieces to enable the interior of the lamination layer of the lamination pieces to generate plastic deforming and the residual compressive stress, all stretching stress can be offset, the fatigue crack extension can be effectively reduced, and the fatigue performance of the laser additive manufacturing component can be improved.

Method used for improving residual compressive stress of laser additive manufacturing component

The invention belongs to the technical field of laser added material manufacturing, and relates to a method for preparing TiAl+Ti2AlNb composite materials by laser melting deposition. The laser melting deposition method is adopted to form the TiAl+Ti2AlNb composite materials; and the feeding quantity of Ti2AlNb is adjusted to achieve a pinning effect in composite material structures to improve overall plasticity of the materials. Meanwhile, circular samples are formed, and scanning paths are changed to concentric arcs to prevent the tensile stress of linear scanning paths of rectangular samples; and concentric circle openings on each layer are converted by 60-90 degrees, that is, the positions of scanning initial points on each layer are changed, so that the thermal stress concentration isreduced to prevent cracks. The heat input quantity in the forming process is controlled, and the substrate preheating temperature in the forming process is adjusted to slow down the formed metal solidification speed and cooling speed, so that the stress is released for a longer time.

Method for preparing TiAl+Ti2AlNb composite materials by laser melting deposition

The invention relates to a reinforcing device and method for selective laser melting added material manufactured components. The reinforcing device comprises a platform, a forming chamber positioned above the platform, and a forming cylinder and a powder holding cylinder positioned under the platform; an upper port of the forming cylinder and an upper port of the powder holding cylinder communicate with the forming chamber; the forming chamber is provided with a laser generation system right above the forming cylinder; the laser generation system comprises a laser probe for selective laser melting, and a laser probe for laser shot blasting; a first base plate and a second base plate capable of moving up and down are arranged in the forming cylinder and the powder holding cylinder; and a forming substrate is arranged above the first base plate. The reinforcing method adds the laser for laser shot blasting in the vacuum forming chamber 4, so that selective laser melting added materials and laser blasted shots alternately work, and components are reinforced at the same time in the forming process; and in addition, the reinforced components are directly heated in the forming chamber 4,so that internal stress in the forming process is reduced, and the mechanical performances of the added material manufactured components are improved.

Huang Shuai

Papers

Progress in additive manufacturing on new materials: A review

In-situ reaction of Ti-Si-C composite powder and formation mechanism of laser deposited Ti6Al4V/ (TiC+Ti3SiC2) system functionally graded material

Method used for improving residual compressive stress of laser additive manufacturing component

Method for preparing TiAl+Ti2AlNb composite materials by laser melting deposition

Reinforcing device and method for selective laser melting added material manufactured components