Search results

This study aims to investigate the wetting behavior of AgCuTi and AgCu filler metals on selective laser melting (SLMed) Ti/TiB₂, and to analyze the microstructure and fracture characteristics of SLMed Ti/TiB₂/AgCuTi or AgCu alloy/SLMed Ti/TiB₂ brazed joints. The wetting behavior of AgCuTi and AgCu filler metals on the selective laser melted (SLMed) Ti/TiB₂ has been studied. The analysis of microstructures and fracture characteristics in vacuum-brazed SLMed Ti/TiB₂ substrate, using AgCuTi and AgCu filler metals, has been conducted to elucidate the influence of brazing temperature and alloy composition on the shear strength of the brazed joints.

Brazing SLMed-Ti/TiB₂ in a vacuum using AgCuTi and AgCu filler metals, this study aims to explore the optimal parameters for brazed joints at various brazing temperatures (800°C−950°C).

The findings suggest that elevated brazing temperatures lead to a more extensive diffusion region in the joint as a result of the partial melting of the filler metal. The joint composition changes from distinct Ti₂Cu layer/TiCu layer/filler metal to a-Ti (ss) + ß-Ti (ss)/TiCu. As the brazing temperature increases, the fracture mode shifts from brittle cleavage to ductile fracture, mainly attributed to a decrease in the CuTi within the brazed joint. This change in fracture behavior indicates an improvement in the ductility and toughness of the joint.

The originality of this study lies in the comprehensive analysis of the microstructure and shear strength of vacuum brazing SLMed Ti/TiB₂ using AgCuTi and AgCu filler metals.

This paper aims to focus on the reliability of Sn15Bi–xAg and Sn15Bi–xCu solder joints during isothermal aging.

The effects of Ag or Cu additions on the microstructure, interfacial metallic compound layer and shear strength of Sn–15Bi (Sn15Bi) based solder joints during were investigated. The effects of Ag or Cu additions on the microstructure and tensile properties of Sn15Bi-based bulk solders were also investigated to provide a comprehensive analysis. The interfacial morphology and microstructure were observed by scanning electron microscopy and the composition in the structure was examined by energy dispersive spectrometer. The shear tests were carried out on the as-soldered and as-aged joints using a ball shear tester.

The results revealed that by adding Ag or Cu, the microstructure of Sn15Bi solder can be refined. Ag addition increased the tensile strength of Sn15Bi solder but had little effect on elongation. However, Cu addition decreased the tensile strength and elongation of Sn15Bi solder. For solder joints, Ag addition increased the shear strength and toughness of Sn15Bi/Cu joints but Cu addition decreased the shear strength and toughness of Sn15Bi/Cu joints.

The authors can potentially provide a replacement for Sn40Pb traditional solder with Sn15Bi solder by alloying Ag or Cu due to its lower cost and similar melting point as Sn–Pb solder.

The purpose of this study is to establish a method for accurately extracting torch and seam features. This will improve the quality of narrow gap welding. An adaptive deflection correction system based on passive light vision sensors was designed using the Halcon software from MVtec Germany as a platform.

This paper proposes an adaptive correction system for welding guns and seams divided into image calibration and feature extraction. In the image calibration method, the field of view distortion because of the position of the camera is resolved using image calibration techniques. In the feature extraction method, clear features of the weld gun and weld seam are accurately extracted after processing using algorithms such as impact filtering, subpixel (XLD), Gaussian Laplacian and sense region for the weld gun and weld seam. The gun and weld seam centers are accurately fitted using least squares. After calculating the deviation values, the error values are monitored, and error correction is achieved by programmable logic controller (PLC) control. Finally, experimental verification and analysis of the tracking errors are carried out.

The results show that the system achieves great results in dealing with camera aberrations. Weld gun features can be effectively and accurately identified. The difference between a scratch and a weld is effectively distinguished. The system accurately detects the center features of the torch and weld and controls the correction error to within 0.3mm.

An adaptive correction system based on a passive light vision sensor is designed which corrects the field-of-view distortion caused by the camera’s position deviation. Differences in features between scratches and welds are distinguished, and image features are effectively extracted. The final system weld error is controlled to 0.3 mm.