Effect of ultrasonic intensity on microstructure and mechanical properties of steel alloy in direct energy deposition-Arc.

To study the effect of ultrasonic intensity on the microstructure and mechanical properties during the direct energy deposition-Arc (DED-Arc) of ER70S-6 steel alloy, an ultrasound assisted DED-Arc system was developed by coupling ultrasonic energy with the electric arc deposition process. The propagation and vibration distribution of ultrasound in the substrate were analyzed by numerical simulation method. Deposition layers were fabricated using different ultrasonic amplitudes, and the microstructure, microhardness and tensile properties of the fabricated parts were systematically investigated.

Microstructure and Mechanical Properties of Gradient Interfaces in Wire Arc Additive Remanufacturing of Hot Forging Die Steel.

Hot forging dies are subjected to periodic thermal stress and often fail in the forms of thermal fatigue, wear, plastic deformation, and fracture. A gradient multi-material wire arc additive remanufacturing method for hot forging dies was proposed to extend the service life of hot forging dies and reduce total production costs. The properties of multi-material gradient interfaces play a critical role in determining the overall performance of the final products.

Laser radius measurement method based on the amplitude jump of a thermal wave.

The laser radius should be calculated with high precision when analyzing the characteristics of a Lamb wave excited by a laser in a thin plate. However, traditional methods for measuring the radius of a laser beam are complex. The paper aims to propose a novel convenient method, to the best of our knowledge, for measuring the radius of a laser ultrasonic beam.

Solid waste shape description and generation based on spherical harmonics and probability density function.

Transport and separation processes of solid waste can only be modelled successfully with discrete element methods in case the shape of the particles can be described accurately. The existing techniques for morphological data acquisition, such as computed tomography, laser scanning technique, optical interferometer, stereo photography and structured light technique, are laborious and require a large amount of realistic solid waste samples. Therefore, there is a pressing need for an alternative method to describe the shape of solid waste particles and to generate multiple variations of particles with almost similar shapes.

A robust identification method for nonferrous metal scraps based on deep learning and superpixel optimization.

End-of-life vehicles (ELVs) provide a particularly potent source of supply for metals. Hence, the recycling and sorting techniques for ferrous and nonferrous metal scraps from ELVs significantly increase metal resource utilization. However, different kinds of nonferrous metal scraps, such as aluminium (Al) and copper (Cu), are not further automatically classified due to the lack of proper techniques.

Operation parameters optimization of a separating system for non-ferrous metal scraps from end-of-life vehicles based on coupled simulation.

End-of-life vehicles (ELVs) provide a particularly potent source of non-ferrous metal scraps. At presents, conveyor belt and air-jet nozzle are widely used in the existing separation system for non-ferrous metal scraps. Parameters such as shape of the scraps, conveyor belt speed (v), nozzle air pressure (P) and nozzle angle (α) have a significant influences on the separating accuracy and efficiency.

Laser Ultrasonic inspection of a Wire + Arc Additive Manufactured (WAAM) sample with artificial defects.

Certain defects like pores, incomplete fusion and micro cracks are sometimes inevitable in Wire + Arc Additive Manufactured (WAAM) components. However, these defects cannot be detected easily by conventional ultrasonic testing due to the rough surface and high temperature of WAAM components. In this paper, a Laser Ultrasonic (LU) system, consist of a pulsed laser and a laser interferometer, is employed to achieve non-contact inspection of artificial defects (crack, flat bottom hole and through hole) in a WAAM sample without surface machining.