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http://dspace.aiub.edu:8080/jspui/handle/123456789/2143| Title: | Micromanufacturing Technology and its Practice |
| Other Titles: | NA |
| Authors: | Hasan, Mahadi |
| Keywords: | Micromanufacturing, Microforming, Micro composite drilling, Micro deep drawing, Nano-particle lubrication condition |
| Issue Date: | 5-Oct-2020 |
| Publisher: | Transtec Publications |
| Citation: | Jiang, Z. Y., Hasam, M., Kamali, H., Jia, F. H., & Xie, H. B. (2020). Micromanufacturing Technology and its Practice. Solid State Phenomena, 311, 12–20. |
| Series/Report no.: | Solid State Phenomena (Volume 311);1 |
| Abstract: | In order to make micro composite drills (Fig. 1), cemented tungsten carbide (WC-10Co) and high strength (AISI 4340) steel were successfully bonded by hot compaction diffusion bonding at a low temperature. The effects of holding time, pressure and temperature on microstructure and mechanical properties of the sintered carbides and bonding strengths of the bimetallic composites were examined, and a transitional layer was found at the interface as a result of elemental inter-diffusion. The optimal bonding parameters were determined to achieve the maximum bonding strength of 226 MPa of the WC-10Co/AISI 4340 steel joints, which is helpful in producing micro composite drills. Microforming is introduced to produce lighter and more energy effective products. In this study, Magnesium-Lithium (Mg-Li) alloy, new material in microscale, was chosen to superior formed micro-cup due to its ultralight weight with outstanding ductility. The dry and oil lubrication conditions were chosen as benchmarks to investigate effects of a novel oil-based nano-particle lubricant in micro deep drawing (MDD) process of Mg-Li alloy. Finite Element (FE) modelling was conducted and the simulation results of the drawing force were in a good agreement with the experimental results. The formed cup quality with consideration on the surface roughness has been extensively evaluated and the results illustrated the quality improvement was substantial. |
| Description: | WC-10Co and AISI 4340 were successfully bonded with no significant microcraks or delamination at the bonding interface. The influences of temperature, time and pressure were analysed on the mechanical properties of the sintered carbides and bonding shear strength. It is found that the increase of the sintering parameters improves the mechanical properties and bonding shear strength. This also promotes the diffusion process that contributes to the growth of reaction layer by inter-diffusion of allowing elements across the joining interface. Neither metallurgical discontinuities nor microcracks exist across the bonding interfaces. Bonding temperature is found to determine a great extent diffusion processes across the bonding interface, and is thus a more influential variable compared to compression pressure and sintering time. Such composite material is helpful for micro composite drill with improved quality and longer service life resulting in substantial cost reduction in microdrilling industries. The as-received and heat treated at 150 °C for 30 min Mg-Li alloy blanks were drawn by MDD process under dry, oil and 2 wt% TiO2 oil-based nano-additive lubrication conditions. The mechanism of the nano-particle resulted in mitigating frictional size effect. The maximum and last stroke drawing forces were reduced and the formed cups’ quality was improved in comparison with the dry condition. The simulation and experimental results were in good agreement. However, when the surface roughness and heterogeneity were increased, a slight variance was detected. |
| URI: | http://dspace.aiub.edu:8080/jspui/handle/123456789/2143 |
| ISSN: | 1662-9779 |
| Appears in Collections: | Publications From Faculty of Engineering |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| 31. DSpace_Publication_Dr. Mahadi_B_Oct.2020-Micromanufacturing Technology and its Practice.docx | 3.01 MB | Microsoft Word XML | View/Open |
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