scholarly journals Poly(methyl methacrylate) Coating of Titanium Workpieces to Reduce Burrs in Micro-drilling

Micromachines ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 838
Author(s):  
Luca Giorleo

A technique to reduce burr height in titanium micro-drilling is presented: a poly (methyl methacrylate) coating was applied before machining on the upper and lower surfaces of a titanium specimen (0.5-mm thick). After drilling, a cleaning process (acetone bath) was executed to eliminate the coating, and holes with less burr were obtained. The coating process was executed with a spin-coating machine. To test the efficacy of the technique, two different coating thicknesses (7.9 and 5.4 μm) and two drill bits (0.25- and 0.5-mm diameter) were evaluated. Qualitative and quantitative analyses of the holes obtained were performed with scanning electron microscopy and three-dimensional microscopy, respectively. The results highlight the efficacy of the technique to reduce the burr height by 70% in coated titanium relative to that in an uncoated titanium sheet.

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1387 ◽  
Author(s):  
M. Galip Icduygu ◽  
Meltem Asilturk ◽  
M. Akif Yalcinkaya ◽  
Youssef K. Hamidi ◽  
M. Cengiz Altan

The three-dimensional nano-morphology of poly(methyl methacrylate; PMMA) microcapsules filled with carbon nanotubes (CNTs) and epoxy resin were investigated by various microscopy methods, including a novel, laser scanning confocal microscopy (LSCM) method. Initially, PMMA microcapsules containing various amounts of CNTs were synthesized by a solvent evaporation method. Scanning electron microscopy analysis showed that pore-free, smooth-surface microcapsules formed with various types of core-shell morphologies. The average size of CNT/epoxy/PMMA microcapsules was shown to decrease from ~52 μm to ~15 μm when mixing speed during synthesis increased from 300 rpm to 1000 rpm. In general, the presence of CNTs resulted in slightly larger microcapsules and higher variations in size. Moreover, three-dimensional scans obtained from confocal microscopy revealed that higher CNT content increased the occurrence and size of CNT aggregates inside the microcapsules. Entrapped submicron air bubbles were also observed inside most microcapsules, particularly within those with higher CNT content.


2011 ◽  
Vol 284-286 ◽  
pp. 2251-2254
Author(s):  
Zhao Gang Nie ◽  
Xin Zhong Li ◽  
Yu Ping Tai ◽  
Ki Soo Lim ◽  
Myeongkyu Lee

The feasibility of three-dimensional optical bit memory is demonstrated by using the change of fluorescence and refractive index in Sm(DBM)3Phen-doped and un-doped Poly(methyl methacrylate). After a femtosecond pulsed laser irradiation, a refractive-index bit and a fluorescent bit can be formed at the same position inside the bulk sample. Multilayer patterns recorded by tightly focusing the pulsed laser beam were read out by a reflection-type fluorescent confocal microscope, which can detect the reflection signal and also the fluorescent signal of the stored bits. The signal-to-noise ratio via the two retrieval modes was compared as a function of recording depth. The stored bits were retrieved with a high signal-to-noise ratio in the absence of any crosstalk and the detection of the fluorescent signal enables retrieval of the stored bits with a higher S/N ratio.


2006 ◽  
Vol 45 (No. 29) ◽  
pp. L765-L767 ◽  
Author(s):  
Wataru Watanabe ◽  
Seiji Sowa ◽  
Takayuki Tamaki ◽  
Kazuyoshi Itoh ◽  
Junji Nishii

2006 ◽  
Vol 103 (1) ◽  
pp. 470-475 ◽  
Author(s):  
Satoshi Koizumi ◽  
Yuji Yamane ◽  
Shigeki Kuroki ◽  
Isao Ando ◽  
Yukihiro Nishikawa ◽  
...  

Materials ◽  
2016 ◽  
Vol 9 (11) ◽  
pp. 948 ◽  
Author(s):  
Kun Zhao ◽  
Xiao-Dong Zhou ◽  
Xue-Qiang Liu ◽  
Lei Lu ◽  
Zhi-Bo Wu ◽  
...  

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1867
Author(s):  
Paula S. S. Lacerda ◽  
Nuno Gama ◽  
Carmen S. R. Freire ◽  
Armando J. D. Silvestre ◽  
Ana Barros-Timmons

Cork is a unique material and its by-products are attracting an ever-growing interest for preparing new materials in an attempt to extend the outstanding properties of cork toward innovative and high value applications. Yet, the miscibility of cork particles with thermoplastic matrices is not easy due to its low density and surface properties. Here, cork is functionalized with poly(methyl methacrylate) (PMMA) via atom transfer radical polymerization (ATRP) to yield cork grafted with PMMA chains particles (cork-g-PMMA). Both the ATRP macroinitiator and the cork-g-PMMA obtained are fully characterized by Fourier-transform infrared spectroscopy (FT-IR), 13C cross-polarized magic-angle spinning solid-state nuclear magnetic resonance (13C CP/MAS solid state NMR), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), X-ray diffraction (XRD) and thermogravimetric analyses (TGA). The functionalized cork particles are then blended with commercial PMMA to afford cork-g-PMMA/PMMA. To compare, cork also is mixed with PMMA and the ensuing cork/PMMA sample and its morphology, thermal, and mechanical properties are compared with those of cork-g-PMMA/PMMA and commercial PMMA. The cork surface modification via ATRP of the methyl methacrylate (MMA) yields better dispersion in the matrix. Consequently, a blend with enhanced mechanical performance, higher thermal stability, and a higher melt flow index (MFI) is obtained when compared to the blend prepared using unmodified particles. The similarity of the MFI of cork-g-PMMA/PMMA to that of PMMA suggests good printability. Indeed, a three-dimensional (3D) printed specimen is obtained confirming that grafting using ATRP is a promising route for the preparation of high quality 3D printed products.


2012 ◽  
Vol 161 ◽  
pp. 292-295 ◽  
Author(s):  
Yong Zhao ◽  
Wei Min Huang ◽  
Hendra Purnawali

We demonstrate a novel approach to fabricate three dimensional (3-D) surface patterns atop poly(methyl methacrylate) (PMMA). This approach utilizes both shape recovery behavior and swelling phenomenon of the PMMA. The simplicity in the fabrication process affirms the low-cost nature of this approach. Moreover, as obtained 3-D patterned PMMA sample can be used as artificial compound eye.


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