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The nickel interlayer improved the laser weldability of Zr-2.5Nb to AISI 410 stainless steel. The fusion zone contained a large amount of refined and tough dendritic γ-Ni(Fe, Cr) solid solution (182 ∼ 268 HV), while the brittle Zr(Fe, Cr)2 intermetallic compound (1171 ∼ 1460 HV), which was the main phase as the result of direct welding of Zr-2.5Nb to SS410 as well as the source responsible for the welding cracks, disappeared. Only limited quantities of Zr2(Ni, Fe), Zr7Ni10 (and/or Zr2Ni7) intermetallics were present mainly in the form of thin layers (less than 200 μm thick in total) near the fusion interface with Zr-2.5Nb. Those Zr-Ni based intermetallics showed relatively higher toughness and lower hardness (301 ∼ 497 HV) than the brittle Zr(Fe, Cr)2, which reduced the overall cracking sensitivity of the laser-weld.

Laser consolidation (LC) is a laser cladding based material additive process that could fabricate a “net-shape” functional metallic part through a “layer-upon-layer” deposition directly from a CAD model. The LC process can produce nickel-base IN-738 superalloy with metallurgical soundness. Nevertheless, due to process-induced rapid directional solidification, the LC IN-738 alloy demonstrates certain unique microstructural characteristics, such as, the presence of non-uniform coarse columnar grains (a majority of the grains is in the range of about 56–158 μm in diameter; but their lengths could vary from several hundred μm to the height of the wall being built up) in combination with exceptionally fine directionally solidified dendrites inside (the secondary dendritic arm spacing is about 1.7 μm). Moreover, the “as-consolidated” LC IN-738 alloy, in nature, is a supersaturated γ solid solution, and any precipitation of γ′ particles from the γ matrix is effectively suppressed. Post heat treatment, thus, is essential to achieve the required operational microstructure. On the other hand, the nature and role of conventional “solution plus aging” treatment to the LC IN-738 alloy seem to be different as compared to “as-cast” or wrought IN-738 alloy. In this paper, process-induced microstructural characteristics of the LC IN-738 alloy and its development brought by post heat treatment were fully investigated. The implication on high-temperature mechanical performance of the LC alloy was discussed as well.

Laser consolidation (LC) is a novel additive manufacturing process being developed by the National Research Council Canada (NRC) at its London facility. LC offers unique capabilities in the production of net-shape functional metallic parts requiring no further post-machining. NRC’s LC technology has achieved dimensional accuracy of up to +/−0.05 mm with a surface finish up to 1 μm Ra (depending on the materials used in the manufacturing process). The LC process differs from other additive manufacturing technologies by its high precision deposition system that can build functional parts or features on top of existing parts using various high performance materials and alloys. In this paper, laser consolidation of various high performance materials (such as Ni-base super alloys and Ti-6Al-4V alloy) will be discussed and the examples will be given on building complex functional components and repairing parts otherwise unrepairable for gas turbine and other applications., ASME Turbo Expo 2015: Turbine Technical Conference and Exposition, June 15–19, 2015, Montreal, QC, Canada

Laser consolidation (LC) developed by National Research Council's Industrial Materials Institute (NRC-IMI-London) since mid-1990s, is a laser cladding based rapid manufacturing and material additive process that could fabricate a "net-shape" functional metallic shape through a "layer-upon-layer" deposition directly from a computer aided design model without using molds or dies. In order to evaluate the LC processability of different materials, some representative nickel-based superalloys (IN-625, IN-718, IN-738, and Waspaloy), stainless steels (austenitic SS316L and martensitic SS420), and lightweight alloys (Ti-6Al-4V titanium alloy and Al-4047 aluminum alloy) have been investigated. Like other laser cladding based processes, due to process-induced rapid directional solidification, the LC alloys have demonstrated certain unique morphological characteristics. Moreover, the "as-consolidated" LC alloys, in nature, are in the "as-quenched" state, and some precipitation processes from their matrices, which are sometimes critical to the development of mechanical performance of the materials, could be effectively suppressed or retarded. Post-heat treatments, therefore, could necessarily facilitate the process of achieving their required operational microstructures. In this article, a comprehensive investigation was performed including metallurgical soundness and process-induced morphological characteristics of the LC materials, and microstructure development brought by post-LC heat treatments using optical microscope, scanning electron microscope, and X-ray diffraction. The implications on the mechanical performance of the LC materials were discussed as well in order to provide essential information for potential industrial applications of the LC materials. © 2011 Her Majesty the Queen.

Pratt and Whitney Canada specializes on the design and manufacturing of aerospace gas turbine engines, which requires advanced technologies to extend components life to reduce maintenance cost. Laser cladding provides unique capabilities for repairing damaged components that currently are difficult or even impossible to be repaired using conventional methods. In this paper, laser cladding of IN-625 alloy was investigated. Testing results reveals that laser clad IN-625 on wrought IN-625 substrate demonstrates comparable or even substantially improved fatigue life as compared to the baseline IN-625 specimens at the room temperature as well as at elevated temperature. Laser clad IN-625 also shows slightly improved wear resistance. Therefore, laser cladding of IN-625 is very attractive for repairing various damaged wrought IN-625 components for aerospace gas turbine engines. A case study will also be presented on laser cladding of IN-625 to repair damaged fuel nozzles that currently can not be repaired using conventional method., 28th International Congress on Applications of Lasers and Electro Optics, November 2-5 2009, Orlando, FL, USA

Laser consolidation (LC) is a laser cladding based novel manufacturing process that produces net-shape functional components directly from a CAD model. As an alternative to conventional machining processes, the LC process builds complete net-shape functional parts or features on existing parts by adding instead of removing material. In this paper, laser consolidation of Waspalloy and IN-718 alloys is demonstrated. The LC process successfully built metallurgically sound Waspalloy and IN-718 alloy samples. The microstructures of as-consolidated and heat-treated Waspalloy and IN-718 materials were examined. Their tensile properties were evaluated and compared with reference data. In addition, several LC Waspalloy and IN-718 samples that are difficult or impossible to make using conventional manufacturing technologies were produced to demonstrate the capability of the process., ICALEO 2008, 27th International Congress on Applications of Lasers and Electro-Optics, Congress Proceedings, October 20th to 23rd, 2008, Temecula, CA, USA

Laser consolidation (LC) is a novel manufacturing process that produces net-shape functional and metallurgically sound components by adding material based on a CAD model. In this paper, laser consolidation of Al 4047 alloy is demonstrated. The LC process successfully built metallurgically sound Al 4047 alloy samples on a Al 6061 substrate. The microstructure of LC Al 4047 material was examined in detail using optical microscope, scanning electron microscope (SEM) and x-ray diffraction (XRD) techniques, while its chemical composition was analysed by x-ray energy dispersive spectroscopy (EDS). The tensile properties of the LC Al 4047 material were evaluated and compared with similar wrought and cast aluminum alloys. In addition, several LC Al 4047 samples were produced to demonstrate the capability of the process. Laser consolidation of Al alloys has many potential applications in aerospace, mold-making and other industries for rapid tooling, small quantity production, and repair of expensive components., ICALEO 2005, October 31st to November 3rd 2005, Miami Florida

Laser consolidation is an emerging novel computer-aided manufacturing process that produces net-shape functional parts layer by layer directly from a CAD model by using a laser beam to melt the injected powder and re-solidifying it on the previous pass. As an alternative to the conventional machining process, this novel manufacturing process builds complete net-shape functional parts or features on an existing part by adding instead of removing material. Ti-6Al-4V alloy is widely used in the aerospace, medical and other industries. In this work, functional properties of laser consolidated Ti-6Al-4V have been investigated. The laser consolidated Ti-6Al-4V material is metallurgically sound and free of cracks and porosity. The components built by the laser consolidated Ti-6Al-4V show good surface finish and dimensional accuracy. The mechanical properties of laser-consolidated Ti-6Al-4V samples are evaluated. The microstructure is analyzed in details using optical microscope, scanning electron microscope (SEM) and x-ray diffraction (XRD). Composition of the laser-consolidated Ti-6Al-4V material is also analyzed by energy dispersive spectroscopy (EDS).Laser consolidation is an emerging novel computer-aided manufacturing process that produces net-shape functional parts layer by layer directly from a CAD model by using a laser beam to melt the injected powder and re-solidifying it on the previous pass. As an alternative to the conventional machining process, this novel manufacturing process builds complete net-shape functional parts or features on an existing part by adding instead of removing material. Ti-6Al-4V alloy is widely used in the aerospace, medical and other industries. In this work, functional properties of laser consolidated Ti-6Al-4V have been investigated. The laser consolidated Ti-6Al-4V material is metallurgically sound and free of cracks and porosity. The components built by the laser consolidated Ti-6Al-4V show good surface finish and dimensional accuracy. The mechanical properties of laser-consolidated Ti-6Al-4V samples are evaluated. The microstructure is analyzed in details using optical microscope, scanning electron microscope (SEM...