scholarly journals Analysis and Characterization of Machined Surfaces with Aesthetic Functionality

2019 ◽  
Vol 13 (2) ◽  
pp. 261-269
Author(s):  
Francesco Giuseppe Biondani ◽  
Giuliano Bissacco ◽  
Lukáš Pilný ◽  
Hans Nørgaard Hansen ◽  
◽  
...  

The generation of fine machined surfaces with high gloss is an important topic in mould manufacturing. The surface gloss can be characterized by means of scattered light sensors and a representative parameter such asAq. In this paper, in-line measurements of scattered light distribution are compared with roughness parameters calculated using a confocal microscope, in order to assess surface aesthetic quality. Several surfaces have been machined by means of high precision milling, producing different surface topographies. Surface characterization has been performed on a machine using a scattered light sensor, and using a confocal microscope in laboratory conditions. The calculatedAqparameter is compared with the amplitude roughness parametersSaandSq, and with hybrid parametersSdqandRdqrepresenting the average slope of the surface features. Scanning electron microscope (SEM) images are used as visual benchmarks to identify the parameters’ correlation with the visual appearance. A different linear trend of the relationship betweenAq,Rdq, andSdqis observed. The description of the surface quality throughSaorSqinstead is found to be insufficient. This is explained by means of SEM pictures showing a dramatic influence of the smeared material over the machined surface.

Author(s):  
Xin Weng ◽  
Xiaoning Jin ◽  
Jun Ni

It is widely observed that today’s engineering products demand increasingly strict tolerances. The shape of a machined surface plays a critical role to the desired functionality of a product. Even a small error can be the difference between a successful product launch and a major delay. Thus, it is important to develop measurement tools to ensure the quality and accuracy of products’ machined surfaces. The key to assessing the quality is robust measurement and inspection techniques combined with advanced analysis. However, conventional Geometrical Dimensioning and Tolerancing (GD&T) such as flatness falls short of characterizing the surface shape. With the advancements in metrology methodology utilizing digital holographic interferometry, large amount of surface data can be captured at high resolution and accuracy without changing platform or technique. This captured High Definition Data (HDD) enables the mining of more valuable information from machined surfaces that most current industry practice cannot achieve in a timely manner. Such new metrology system opens the torrent of observable events at plant floor and increases the transparency of machining processes. This presents great opportunities to characterize machined surface into a new level of details, which can be applied in production quality evaluation and process condition monitoring and control. This research work proposes a framework of a multi-scale surface characterization for surface quality evaluation and process monitoring. Case studies are presented to show how proposed metrics could be applied in surface quality evaluation and process monitoring.


2004 ◽  
Vol 847 ◽  
Author(s):  
Svetlana Khvan ◽  
Sang-Soo Lee ◽  
Junkyung Kim

ABSTRACTComplete delamination of clay in polymer matrix has been strongly prohibited due to strong adhesion of guest polymer chains between hydrophilic clay as well as degradation and desorption of organic materials in the gallery at high temperature. Incorporation of charged nanosized polystyrene beads directly into the gallery of pristine clay through exfoliation-exchange mechanism has been proposed to overcome the drawbacks.Synthesis of polymer nanobeads via emulsifier-free emulsion polymerization allowed to achieving formation of particles of appropriate particle size and surface charge density. Surface characterization, performed with XPS and ToF SIMS, has provided the results on the existence and the nature of the functional groups on the polymer particle surface, which have been found to be in a good compliance.Morphology of polymer-incorporated clay was observed from TEM, FE-SEM images. Study on mechanism of incorporation via XRD, XPS, ToF-SIMS suggested that adsorption of polymer nanobeads through cationic exchange of intergallery cation of clay for onium ion at the surface of polymer nanobead not only improves compatibility of clay with polymer matrix, but, what is essential, dramatically promotes expansion of clay gallery.


Author(s):  
Shigehiko Sakamoto ◽  
Atsushi Yokoyama ◽  
Kazumasa Nakayasu ◽  
Toshihiro Suzuki ◽  
Shinji Koike

Abstract The establishment of international standards for 5-axis control machining centers has been supported by the high interest of each country. Internationally, various accuracy inspection methods have been proposed and widely discussed. Accuracy measuring devices for these purposes have also been proposed. In 2014, inspection methods for 5-axis machines were published in ISO 10791-6 and 10791-7. In this research, we propose a test method to process 9 square faces as a new accuracy evaluation method. We simulate the influence of assembly error by the proposed square 3 × 3 machining method on the machined surface. By processing 9 square faces with different tool angle on the same plane, it was possible to evaluate the influence of assembly errors in the 5-axis machining center on the machined surface. Nine surfaces machined by the square 3 × 3 processing method cause differences in surface height due to alignment errors. In addition, nine machined surfaces become all diagonal not parallelism. The alignment errors of the 5-axis machining center is identified by evaluating the orientation of the machined surfaces. Specifically, we propose a newly method to measure the height difference of nine surfaces. Then, the possibility of identifying the alignment error of the 5-axis machining center using the measurement results is shown.


2019 ◽  
Vol 895 ◽  
pp. 313-318
Author(s):  
S.B. Supriya ◽  
S. Srinivas

Stainless Steels are possessing fabrication flexibility, high hardness, durability, low maintenance, high strength and resistance to heat and corrosion. This alloy steel is extensively used in various engineering applications. Some of the conventional machining techniques results in loss of original properties of stainless steel work material and makes it to behave like ordinary material within the machined surface. Machining of Stainless steels is more challenging due to its high alloying content. Problems such as application of huge coolant supply and poor chip breaking while machining, work hardening in work material, use of cutting tools with varying tool signature, results in enhanced production cost and time. Further, it is important to ensure that there is no machine tool-cutting tool vibration leading to edge chipping of cutting tool. To avoid all these problems, Abrasive water jet machining (AWJM) is used. This paper presents the machining capabilities of AWJ on Stainless Steel304. Influence of dynamic input parameters such as jet pressure, speed of traverse and abrasive flow rate on the depth of cut is investigated. An empirical model is proposed for depth of cut and an error analysis is done with measured and modeled values of depth of cut. It was found that traverse speed influences more than other parameters. SEM images indicated smooth surface at entrance and waviness at exit side. The model proposed predicts the depth of cut more or less accurately.


2019 ◽  
Vol 27 (01) ◽  
pp. 1950081 ◽  
Author(s):  
CHUNHUI JI ◽  
SHUANGQIU SUN ◽  
BIN LIN ◽  
TIANYI SUI

This work performed molecular dynamic simulations to study the 2D profile and 3D surface topography in the nanometric cutting process. The least square mean method was used to model the evaluation criteria for the surface roughness at the nanometric scale. The result showed that the cutting speed was the most important factor influencing the spacing between the peaks, the sharpness of the peaks, and the randomness of the profile. The plastic deformation degree of the machined surface at the nanometric scale was significantly influenced by the cutting speed and depth of cut. The 2D and 3D surface roughness parameters exhibited a similar variation tendency, and the parameters Ra and Rq tended to increase gradually with an increase in the cutting speed and a decrease in the depth of cut. Finally, it is concluded that at the nanometric scale, the 3D surface roughness parameters could more accurately reflect the real surface characteristics than the 2D parameters.


2012 ◽  
Vol 248 ◽  
pp. 504-510 ◽  
Author(s):  
Valentin Mereuta ◽  
Mihaela Buciumeanu ◽  
Liviu Palaghian

The influence of machined surface roughness on the fatigue life of S355JR steel has been investigated. The specimen have been machined with three roughness levels and tested under plane fatigue. The surface roughness parameters were used to estimate the effective stress concentration factors Kt using the Arola-Ramulu model and Neuber model. In this paper it is proposed a modification for both models. Based on the experimental results was obtained the evolution of the effective stress concentration factor for the original Arola-Ramulu and Neuber models and also for the modified ones.


1999 ◽  
Vol 23 (1A) ◽  
pp. 37-50
Author(s):  
S. Kurada ◽  
C. Bradley

A non-contact measurement technique was developed for the in-cycle assessment of ground surface texture. The system utilises off-the-self vision components to capture the pattern of scattered light from the surface, which is illuminated by a white light source at a shallow grazing angle. Three parameters, related to the surface texture, were derived from the pattern and correlation curves were established by plotting the three textural parameters against the corresponding average surface roughness Ra obtained from a stylus profilometer. A set of test samples, ground to a pre-determined roughness, were used to estimate the efficacy of the measurement technique. The proposed technique is fast and reliable means of extracting textural information from ground surfaces and, furthermore, it can be easily adapted to use in a production environment.


2015 ◽  
Vol 809-810 ◽  
pp. 93-98
Author(s):  
Ionuţ Urzică ◽  
Ciprian Râznic ◽  
Mihai Apostol ◽  
Corina Mihaela Pavăl ◽  
Mihai Boca ◽  
...  

Frequently, on the drawings of mechanical parts, only indications concerning the surface roughness parameter Ra and, relatively rarely, the surface roughness parameter Rz are included. However, the study of the machined surface roughness highlights the necessity to use yet other surface roughness parameters, in order to have a clearer image on the state of the machined surface. Some other surface roughness parameters possible to be used and presenting importance, without the parameters Ra and Rz, were highlighted. One took into consideration the possibility of measuring parameters Rsk and Rmr by means of the available surface roughness testers. Experimental researches of turning by applying the method of full factorial experiment were developed. As input factors in turning process, the cutting speed, the feed rate and the tool nose radius were used. The experimental results were mathematically processed, being determined empirical mathematical models that highlight the influence of certain input factors of turning process on the values of some surface roughness parameters characterized by a more restricted use


Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 840 ◽  
Author(s):  
José Henrique de Lima Cavalcanti ◽  
Patrícia Matos ◽  
Cresus Vinícius Depes de Gouvêa ◽  
Waldimir Carvalho ◽  
José Luis Calvo-Guirado ◽  
...  

Manipulation of implant surface characteristics constitutes a promising strategy for improving cell growth and tissue response on a variety of materials with different surface topographies. Mesenchymal progenitor cells with a capacity to respond to titanium surface stimuli and differentiate into osteoblasts were used to perform comparative tests between two different implant topographies, including their functional interaction with pre-osteoblasts directly seeded onto the implants. Functional analysis of nanostructured implant surfaces was performed by in vitro assay analysis. The machined surface of titanium implants (mach group) was used as a control and compared with a nanoparticle HA activated surface implant (nano group), developed by the deposition of pure crystalline hydroxyapatite. Cell culture on the nano group surface resulted in higher cell adhesion and cultured osteoblast viability compared with the mach group. Scanning electron microscope (SEM) images revealed a stable interaction, indicated by the presence of focal cell adhesion formation. These results together with positive mineralization assays showed the nano group to be an excellent scaffold for bone-implant integration.


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