Composite Micro-Machining Technology on the Non-Silicon MEMS

Background: Patch antennas are composed of the substrate material with patch and ground plane on the both sides of the substrate. The dimensions and performance characteristics of the antenna are highly influenced by the choice of the appropriate substrate depending upon the value of their dielectric constant. Generally, low index substrate materials are used to design the patch antenna but there are also some of the applications, which require the implementation of patch antenna design on high index substrate like silicon and gallium arsenide. Objective: The objective of this article is to review the design of antennas developed on high index substrate and the problems associated with the use of these materials as substrate. Also, main challenges and solutions have been discussed to improve the performance characteristics while using the high index substrates. Method: The review article has divided into various sections including the solution of the problems associated with the high index substrates in the form of micro-machining process. Along with this, types of micro machining and their applications have discussed in detail. Results: This review article investigates the various patch antennas designed with micro-machining technology and also discusses the impact of micro-machining process on the performance parameters of the patch antennas designed on high index substrates. Conclusion: By using the micro-machining process, the performance of patch antenna improves drastically but fabrication and tolerances at such minute structures is very tedious task for the antenna designers.

Download Full-text

Study of micro machining characteristics by Nd-YAG Laser on NiTinol shape memory alloy

Advances in Materials and Processing Technologies ◽

10.1080/2374068x.2021.1946757 ◽

2021 ◽

pp. 1-15

Author(s):

Subhadip Pradhan ◽

Piyush Bhusan Dash ◽

Kanchan Kumari ◽

Debabrata Dhupal

Keyword(s):

Shape Memory Alloy ◽

Shape Memory ◽

Micro Machining ◽

Yag Laser ◽

Machining Characteristics

Download Full-text

FEM and Analytical Modeling of the Incipient Chip Formation for the Generation of Micro-Features

Materials ◽

10.3390/ma14143789 ◽

2021 ◽

Vol 14 (14) ◽

pp. 3789

Author(s):

Michele Lanzetta ◽

Marco Picchi Picchi Scardaoni ◽

Armin Gharibi ◽

Claudia Vivaldi

Keyword(s):

Material Properties ◽

Analytical Modeling ◽

Cutting Tool ◽

Sustainable Manufacturing ◽

Cutting Parameters ◽

Micro Machining ◽

Machining Processes ◽

Steel Alloys ◽

Diamond Blade ◽

Micro Features

This paper explores the modeling of incipient cutting by Abaqus, LS-Dyna, and Ansys Finite Element Methods (FEMs), by comparing also experimentally the results on different material classes, including common aluminum and steel alloys and an acetal polymer. The target application is the sustainable manufacturing of gecko adhesives by micromachining a durable mold for injection molding. The challenges posed by the mold shape include undercuts and sharp tips, which can be machined by a special diamond blade, which enters the material, forms a chip, and exits. An analytical model to predict the shape of the incipient chip and of the formed grove as a function of the material properties and of the cutting parameters is provided. The main scientific merit of the current work is to approach theoretically, numerically, and experimentally the very early phase of the cutting tool penetration for new sustainable machining and micro-machining processes.

Download Full-text

Multilayer Diamond Coatings Applied to Micro-End-Milling of Cemented Carbide

Materials ◽

10.3390/ma14123333 ◽

2021 ◽

Vol 14 (12) ◽

pp. 3333

Author(s):

Eduardo L. Silva ◽

Sérgio Pratas ◽

Miguel A. Neto ◽

Cristina M. Fernandes ◽

Daniel Figueiredo ◽

...

Keyword(s):

Electron Microscopy ◽

End Milling ◽

Interfacial Stress ◽

Cemented Carbide ◽

Air Cooling ◽

Micro Machining ◽

Diamond Coatings ◽

Wear Properties ◽

High Adhesion ◽

Micro End Milling

Cobalt-cemented carbide micro-end mills were coated with diamond grown by chemical vapor deposition (CVD), with the purpose of micro-machining cemented carbides. The diamond coatings were designed with a multilayer architecture, alternating between sub-microcrystalline and nanocrystalline diamond layers. The structure of the coatings was studied by transmission electron microscopy. High adhesion to the chemically pre-treated WC-7Co tool substrates was observed by Rockwell C indentation, with the diamond coatings withstanding a critical load of 1250 N. The coated tools were tested for micro-end-milling of WC-15Co under air-cooling conditions, being able to cut more than 6500 m over a period of 120 min, after which a flank wear of 47.8 μm was attained. The machining performance and wear behavior of the micro-cutters was studied by scanning electron microscopy and energy-dispersive X-ray spectroscopy. Crystallographic analysis through cross-sectional selected area electron diffraction patterns, along with characterization in dark-field and HRTEM modes, provided a possible correlation between interfacial stress relaxation and wear properties of the coatings. Overall, this work demonstrates that high adhesion of diamond coatings can be achieved by proper combination of chemical attack and coating architecture. By preventing catastrophic delamination, multilayer CVD diamond coatings are central towards the enhancement of the wear properties and mechanical robustness of carbide tools used for micro-machining of ultra-hard materials.

Download Full-text

Micro-machining using 1.55μm band fiber pulse laser with 10kW peak power

10.1117/12.596380 ◽

2004 ◽

Cited By ~ 1

Author(s):

Junya Maeda ◽

Hisashi Sawada ◽

Minoru Yoshida ◽

Moriyuki Fujita

Keyword(s):

Pulse Laser ◽

Peak Power ◽

Micro Machining

Download Full-text