Juchen Zhang

To achieve remanufacturing of damaged alloy steel stamping die, laser cladding repair technology has emerged. However, conventional laser cladding repair may result in an increase in porosity and microcracks on the surface undergoing repair. The present study investigated the potential of laser shock strengthening treatment on the surface of laser cladding repair molds. This treatment could reduce surface defects and introduce residual compressive stress to strengthen the mold surface. The experimental results demonstrated that the grain structure of the melted surface underwent significant refinement following laser shock strengthening treatment, with a substantial increase in microhardness from 541.26 to 760.54 HV. Furthermore, residual compressive stresses of −496 MPa were introduced. Furthermore, the corrosion resistance and friction wear performance of the sample surface were enhanced. The corrosion current density decreased by approximately 18%, the polarization resistance increased by around 73.84%, and the surface friction wear coefficient was significantly reduced. Concurrently, a numerical model of the laser shock process was established by Abaqus to simulate the spatial distribution of residual compressive stress on the sample surface. The experimental results exhibited a high degree of consistency with the simulation results.

Electrochemical machining (ECM) offers a novel solution for forming and manufacturing aero-engine narrow-channel blisks from difficult-to-machine titanium alloys due to its non-contact processing method. This study investigates the electrochemical dissolution and machining characteristics of α + β titanium alloy TC11, using TC4 and TC6 for comparison in 10% NaCl solution. Potentiodynamic polarization tests revealed TC11 had the highest decomposition voltage (>7 V). Electrochemical impedance and XPS analyses confirmed a dual-layer passivation film structure on all alloys, with TC11 exhibiting significantly higher film resistance, indicating superior corrosion resistance. In pulse ECM of narrow blade channels, TC11 demonstrated the best machining accuracy, yielding the smallest channel width (3.68 mm), taper (0.59 mm) and taper angle 4.59°, alongside the lowest surface roughness (3.973–5.186 μm). This is attributed to its highly stable passivation film, which minimizes stray corrosion. The results establish TC11 as a promising material for high-precision electrochemical machining applications.

In this study, low-viscosity hydrodynamic fluid film generation behaviors and frictional properties of spiral-groove textured surface considering roughness were investigated theoretically and experimentally. A lubrication model incorporating the average Reynolds equation, the Greenwood–Tripp asperity contact model, and the Jakobsson–Floberg–Olsson cavitation boundary was developed to analyze the influence of critical operational conditions and geometric parameters on hydrodynamic lubrication behaviors and frictional properties, which can support the identification of lubrication regimes and the optimization of spiral-groove textures under water lubrication. Theoretical results revealed that the transition from mixed to full hydrodynamic lubrication is highly dependent on rotational speed, surface roughness, and applied load. Optimization of groove depth, spiral angle, and groove-to-weir ratio could promote the formation of stable film and friction reduction under low-viscosity lubrication, where challenges such as reduced film thickness, cavitation, and roughness effects need to be carefully considered. An experimental device to investigate the fluid film generation behaviors and a specific calibration procedure to determine fluid film thickness were developed. Experimental results further indicate that clockwise rotation facilitates fluid pumping and increases film thickness, while a larger number of grooves effectively enhances the hydrodynamic effect and lowers the friction coefficient. Combined with a rotating-type tribometer, the theoretical prediction reliability of fluid film thickness and frictional performance variation laws were verified accordingly.

With the increasing demand for high-specific-strength materials for high-temperature applications, particularly in the aerospace field, novel (TiVCrZr)_100−xW_x (x = 5, 10, 15 and 20) refractory high-entropy alloys (RHEAs) were developed. The phase formation, microstructure, and mechanical properties were studied. The (TiVCrZr)_100−xW_x RHEAs exhibit a relatively high specific strength and low density compared with the W-containing RHEAs and most of the W-free RHEAs. In (TiVCrZr)_100−xW_x RHEAs, Laves, BCC and Ti-rich phases are formed, where the Laves phase is the major phase, and the volume fraction of the BCC phase increases with increasing W content. (TiVCrZr)_100−xW_x RHEAs exhibit dendrite structures, where W is enriched in the dendrite region, and increasing W-rich precipitations corresponding to the BCC phase are observed. The improvement of the strength and hardness of RHEAs is mainly attributed to the evolution of the microstructure and corresponding strengthening effect of W. The empirical parameters and calculated phase diagram were investigated, which further explain and verify the formation and variation of phases. The present findings give more insights into the formation of multi phases in (TiVCrZr)_100−xW_x RHEAs, and explore their application potential in the aerospace industry and nuclear reactors due to their high specific strength and low-activation constituent elements.

To achieve energy-saving production, one critical step is to calculate and analyze the energy consumption and energy efficiency of machining processes. However, considering the complexity and uncertainty of discrete manufacturing job shops, it is a significant challenge to conduct data acquisition and energy consumption data processing of manufacturing systems. Meanwhile, under the growing trend of personalization, social manufacturing is an emerging technical practice that allows prosumers to build individualized services with their partners, which produces new requirements for energy data processing. Thus, a real-time energy consumption characteristic analysis method in intelligent workshops for social manufacturing is established to realize data processing and energy efficiency evaluation automatically. First, an energy-conservation production architecture for intelligent manufacturing processes is introduced, and the configuration of a data acquisition network is described to create a ubiquitous manufacturing environment. Then, an energy consumption characteristic analysis method is proposed based on the process time window. Finally, a case study of coupling-part manufacturing verifies the feasibility and applicability of the proposed method. This method realizes a combination of social manufacturing and real-time energy characteristic analysis. Meanwhile, the energy consumption characteristics provide a decision basis for the energy-saving control of intelligent manufacturing workshops.