- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Cladding of Stellite-6/WC Composites Coatings by Laser Metal Deposition
摘要： This study aims to investigate the microstructure and hardness of multi-layered Stellite-6/WC metal-matrix composites coatings on metallic substrates cladded by laser metal deposition (LMD) for improvement of wear and corrosion resistances. As coating materials, Stellite-6 and WC-12wt.%Co powders were selected. Powder mixtures having various mixing-ratios of Stellite-6 and WC-12wt.%Co were provided vertically on S45C substrates by controlling powder feeding rates of the two powder feeders, individually. Stellite-6/WC composites which consist of three layers with different compositions were cladded on the S45C substrates by laser melting. Cross-sectional microstructure observation was carried out by using an optical microscope (OM). Vickers microhardness tests were conducted to evaluate hardness of the cladding layers and substrates. The experimental results demonstrate that hard multi-layered Stellite-6/WC metal-matrix composites coatings were successfully cladded on the S45C substrates. Property gradients in the Stellite-6/WC composites could be made due to the position-dependent chemical composition and microstructure made by controlling powder feeding rates of an LMD system.
关键词： Cladding,Additive Manufacturing (AM),Metal Matrix Composites (MMC),Laser Metal Deposition (LMD),Hard Materials
更新于2025-09-23 15:22:29
-
Surface based variable thickness slicing modeling for laser metal deposition
摘要： Laser metal deposition (LMD) has been a promising additive manufacturing technology widely used in mold rapid manufacturing. In order to improve the capacity of LMD for complex curved surface structures, a surface based variable thickness slicing (S-VTS) model is proposed to adaptively generate the LMD process based on the geometric characteristics of structures. Two deposition strategies in scanning and overlapping directions are designed to enable variable thickness of each cladding layer by dynamically adjusting the scanning speed and overlapping rate. To improve the surface quality and forming efficiency, the discrete particle swarm optimization (DPSO) algorithm is adopt to optimize the process parameters of S-VTS model, including the number of cladding layer, scanning pass, and segment per pass. Several experiments are conducted to form the cuboid samples with wavy and freeform surface and verify the feasibility of the S-VTS model. The results demonstrate that under the open-loop control condition, the geometric accuracy, surface quality, and efficiency of the proposed method is improved in comparison with uniform thickness slicing (UTS) deposition. Moreover, heterogeneous microstructure is always generated by the S-VTS method in terms of grain size and growth direction.
关键词： Variable thickness slicing (S-VTS),Laser metal deposition (LMD),Curved surface,Mold
更新于2025-09-23 15:19:57
-
Application of Laser Metal Deposition for a New Model of Assembled Camshaft
摘要： This work introduces the invention of an alternative camshaft manufacturing method aimed at improving the efficiency of the process and providing a more flexible product. The innovation consists in the laser metal deposition (LMD) of a profile on the shaft in order to realize a coupling stretch where the cam is fixed by interference. Alternative profile materials (1.4404 steel and Inconel 625 alloy) are deposited on a 1.0421 steel tube at different laser power levels and powder flow rate. The effect of the process parameters on the deposited profile is investigated initially through the evaluation of indirect quality attributes, such as deposit dimensions, hardness values, and microstructure. Then, the coupling force resulting from the press-fit test is evaluated. Finally, the best configuration of this new assembled camshaft is tested with a torsion test rig. Performances of the new assembled camshaft are compared with those of traditional products, leading to the validation of this innovative solution. The preliminary feasibility of the LMD application to the production of an assembled camshaft is demonstrated.
关键词： additive manufacturing,cladding,hardness,testing,laser metal deposition (LMD),dilution
更新于2025-09-16 10:30:52
-
In-process height control during laser metal deposition based on structured light 3D scanning
摘要： Laser metal deposition is an additive manufacturing process capable of layer by layer construction of solid parts. An incorrect deposition distance between nozzle and substrate can result in height deviations from the ideal building path. The error can be propagated along layers, leading to an irreversible defect. Maintaining an optimal distance between the nozzle and the substrate is therefore a critical aspect. This paper introduces an off-line geometric control system for in-process measurement and build path correction. A structured light based 3D scanner measures the build height from an external, fixed position, providing more precise results than moving measuring systems. The deposition is stopped in certain stages of the process and the piece is scanned generating a three-dimensional point cloud. Processing of the collected data allows the build height determination. A control algorithm was developed to take corrective actions in accordance with the measured error. The system enables an accurate control of the generated geometry and permits the comparison with the original computer design. This approach reduces the required human supervision during the process and the occurrence of non-valid parts. The effectiveness of the method was proved through the contrast of parts built with and without control, showing a more accurate reproduction of the generated solid parts when corrections are applied.
关键词： monitoring,Laser Metal Deposition (LMD),additive manufacturing,control,metrology,structured light,3D scanning
更新于2025-09-12 10:27:22