• Journal of the Korean Wood Science and Technology
• /
• v.8 no.1
• /
• pp.22-27
• /
• 1980

Quantitative assessment of edge blunting of saw-teeth was carried out by TALYSURF. 1. Using the following equation, the real shape of a saw-tooth can be traced on the graph of TALYSURF. ${\frac{{\Delta}h}{h}}={\frac{V{\Delta}_x}{V_x}}$ {${\Delta}h$: vertical distance of stylus h: vertical distance in chart $V{\Delta}_x$: Velocity of stylus $V_x$: velocity of chart} 2. As shown on Fig 2, the error from stylus itself can be calculated by following equation. i) 13.8${\mu}{\leqq}$x<20.4${\mu}$ y=-0.2246x+4.59${\mu}$ ii) 0${\leqq}$x<13.8${\mu}$ y=${\sqrt{(-18{\mu})^2-x^2}}-1.42x+32.7{\mu}}$ 3. The relationship between profile of saw-tooth and error from stylus itself can be calculated by following equation. $E(%)=\frac{f(r){\times}{\frac{4}{18{\mu}}}}{f(R){\times}{\frac{R}{18.5{\mu}}}-f(r){\times}{\frac{r}{18{\mu}}}}{\times}100$ {E(%)${\frac{error\;of\;stylus}{dullness\;of\;saw\;tooth}}{\times}100$ r: radius of stylus tip R: radius of tip which is drawn in graph of talysurf f(r) : error of stylus f(R) : dullness of tip which is drawn in graph of talysurf} 4. The graph of maximum error and profile of saw-tooth was parabola.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.4 no.2
• /
• pp.10-15
• /
• 2005

For the development of compensation machining program, ultra precision grinding used in ultra precision machine and corrective machining was studied. We explored a new rough grinding technique on optical material such as zerodur. The facility used is a polishing machine with a custom grinding module and a range of diamond resin bond wheel. Surface roughness and form accuracy are measured by surface measurement equipment(Form Talysurf series2). Our compensation machining program has complied with a target of producing surface roughness better than $0.05{\mu}m$ Ra and form accuracy of around $0.05{\mu}m$ Rt and has been unveiled as a work-hour model.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2003.04a
• /
• pp.405-409
• /
• 2003

We explored a new rough grinding technique on optics materials such as Zerodur. The facility used is a NANOFORM-600 diamond turning machine with a custom grinding module and range of diamond resin bond wheel. The grinding parameters such as workpiece rotation speed depth of cut and feed rate were altered while grinding the workpiece surfaces of 20m in diameter. Surface roughness is measured by Form Talysurf series2. Our target is to define grinding conditions producing the surface roughness better than 0.02${\mu}{\textrm}{m}$ Ra and the form accuracy of around 0.2${\mu}{\textrm}{m}$ PV.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.4 no.1
• /
• pp.13-17
• /
• 2005

We explored a new rough grinding technique on optics materials such as Zerodur. The facility used is a NANOFORM-600 diamond turning machine with a custom grinding module and a range of diamond resin bond wheel. The grinding parameters such as workpiece rotation speed, depth of cut and feed rate were altered while grinding the workpiece surfaces of 20mm in diameter. Surface roughness was measured by Form Talysurf series2. Our target is to define grinding conditions producing the surface roughness smaller than $0.2{\mu}m$ Ra.

• International Journal of Precision Engineering and Manufacturing
• /
• v.9 no.2
• /
• pp.39-43
• /
• 2008

Atmospheric pressure plasma polishing (APPP) is a noncontact precision machining technology that uses low temperature plasma chemical reactions to perform atom-scale material removal. APPP is a complicated process, which is affected by many factors. Through a preliminary theoretical analysis and simulation, we confirmed that some of the key factors are the radio frequency (RF) power, the working distance, and the gas ratio. We studied the influence of the RF power and gas ratio on the removal rate using atomic emission spectroscopy, and determined the removal profiles in actual operation using a commercial form talysurf. The experimental results agreed closely with the theoretical simulations and confirmed the effect of the working distance. Finally, we determined the element compositions of the machined surfaces under different gas ratios using X-ray photoelectron spectroscopy to study the influence of the gas ratio in more detail. We achieved a surface roughness of Ra 0.6 nm on silicon wafers with a peak removal rate of approximately 32 $mm^{3}$/min.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.18 no.1
• /
• pp.76-82
• /
• 2009

To obtain the surface roughness with nano order, we need a ultra-precision machine, cutting condition, and materials. In this paper, the cutting condition for getting nano order smooth surface of core have been examined experimentally by the ultra-precision machine and diamond wheels. The effects of the cutting velocity, the feed rate and depth of cut on the surface roughness were studied. And also, the surface roughness was measured by the Form Talysurf series PGI 840. The champion data of developed core was surface roughness Rmax 24.6nm, figure accuracy Rmax 68.9nm.

• Journal of the Korean Society for Precision Engineering
• /
• v.19 no.10
• /
• pp.195-201
• /
• 2002

This paper deals with the precision grinding for aspherical surface of optical parts. A parallel grinding method using the spherical wheel was suggested as a new grinding method. In this method, the wheel axis is positioned at a $\pi$/4 from the Z-axis in the direction of the X-axis. An advantage of this grinding method is that the wheel used in grinding achieves its maximum area, reducing wheel wear and improving the accuracy of the ground mirror surface. In addition, a truing by the CG (curve generating) method was proposed. After truing, the shape of spherical wheel transcribed on the carbon is measured by the Form-Talysurf-120L. The error of the form in the spherical wheel which is the value ${\Delta}x$ and $R{^2}{_y}$ inferred from the measured profile data is compensated by the re-truing. Finally, in the aspherical grinding experiment, the WC of the molding die was examined by the parallel grinding method using the resin bonded diamond wheel with a grain size of ＃3000. A form accuracy of 0.16${\mu}m$ P-V and a surface roughness of 0.0067${\mu}m$ Ra have been resulted.

• Journal of the Korean Society for Precision Engineering
• /
• v.29 no.12
• /
• pp.1267-1271
• /
• 2012

Demand for optical glass device used for lighting could increase rapidly because of LED lighting market growth. The optical glass devices that have been formed by hot press molding process the desired optical performance without being subjected to mechanical processing such as curve generation or grinding. EL-Max material has been used for many engineering applications because of their high wear resistance, high compressive strength, corrosion resistant and very good dimensional stability. EL-Max is very useful for a glass lens mold especially at high temperature and pressure. The performance and reliability of optical components are strongly influenced by the surface damage of EL-Max during grinding process. Therefore, the severe process condition optimization shall be necessary for the highly qualified EL-Max glass lens mold. To get the required qualified surface of EL-Max, the selection of type of the diamond wheel is also important. In this paper, we report best grinding conditions of ultra-precision grinding machining. The grinding machining results of the form accuracy and surface roughness have been analyzed by using Form Talysurf and NanoScan.

• Journal of Periodontal and Implant Science
• /
• v.29 no.3
• /
• pp.607-621
• /
• 1999

This study examined the human fibroblasts cell attachment to commercially pure titanium surface which had been instrumented by 3 types of periodontal instruments. Commercially pure titanium plates were uniformly scaled using plastic, stainless steel, titanium curette. these all experimental groups 65 undirectional strokes with the designated curettes. Alteration of the surfaces due to instrumentation was evaluated by Form Talysurf(R) and reported as Ra value(mean surface roughness). Then other experimental groups were immersed in a cell suspension of human gingival fibroblasts($1{\times}10^5$ cell/ml). After 3 days of culture, cell attachment and morphology was observed by SEM, and attached cell were counted by Hemocytometer. A significant difference in mean Ra value was observed for surface instrumented by metal curette compared to either control surface or surface instrumented by the plastic curette(P<0.01). No stastically significant difference was noted between control surface and those instrumented by the plastic curette. SEM observation showed that cell morphology and attachment to the commercially pure titanium plate was similar appearance on the all experimental groups. Experimental groups instrumented by titanium curette and stainless steel curette were more attached cell number than control group, but experimental group instrumented by plastic curette were similar with control groups(P<0.01). In summary, metal curette produced an significant alteration of the commercially pure titanium surface and more favorable surface topography for cell attachment. Otherwise plastic curette was insignificantly altered the commercially pure titanium surface(P<0.01).

• Journal of Periodontal and Implant Science
• /
• v.29 no.3
• /
• pp.621-636
• /
• 1999

When mucoperiosteal flaps are positioned and sutured to desirable position, the wound contains several interface between tissues which differ fundamentally in composition & biological reaction. Thus the C-T surface of the flap will, on one hand, oppose another vascularized surface, and on the other, the avascular dental material for example, when root resoptions, fractured root, endodontic perforation, deep root carious lesions were filled with amalgam, glass ionomer, resin etc. Recently, a number of case report described the successful treatment of a subgingival root lesion with restorative material & free gingival graft, open flap surgery, but more objective research was needed . Most of study on restorative materials were concerned for cytotoxicity not for actual healing event on that materials and its influencing factors such as biocompatibility, surface wettability, surface topography . The aim of this in vitro study was to evaluate the effect of amalgam, resin modified glass ionomer, composite resin per se, and their surface roughness on the growth of human gingival fibroblast. The cells were obtained and placed on culture flask and incubated for 3 days with the prepared test materials. Then count the attached cell number with hemocytometer,(n=12) and 2 samples were examined with SEM about attachment cell morphology . Another 4 samples were evaluated on their surface roughness with Talysurf and average surface roughness value(Ra) were obtained. Statistical difference in attached cell number, roughness value were analyzed using ANOVA. The number of attached cell was as follows, for root dentin specimen 16.7${\pm}$4.41, resin modified glass ionomer 14.0${\pm}$4.15, resin 8.13${\pm}$3.63, amalgam 0.72${\pm}$3.33(${\times}10^3$). Between root dentin and resin-modified glass ionomer, no significant difference was observed, but resin, amalgam showed a significant less cell numbers than for root dentin, resin modified glass ionomer cement. SEM examination expressed many cell surface attachment apparatus in root dentin and resin modified glass ionomer specimens. For resin specimen, cell attachment was observed but exposed less appratus. The average surface roughness value are following results. Dentin specimen 0.6972${\pm}$ 0.104, resin modified glass ionomer 0.0822${\pm}$0.009, resin 0.0875${\pm}$0.005, amalgam 4.2145${\pm}$0.985(${\mu}m$). Between root dentin, resin-modified glass ionomer, and resin, no significant difference was observed, but amalgam showed a significant more rough surface than other groups. When evlauated the interrelationship between cell attachment and surface roughness, therefore, there was weak reverse correlation.(pearson correlation : - 0.593) These results suggest that resin modified glass ionomer have the favorable healing potential when used for subgingival restoration. And for relationship between cell attachment and surface characteristics, further investigations were needed.