scholarly journals Innovative fabrication of diffractive surfaces on plastic parts via textures micromilled on NiP injection moulds

2021 ◽  
Author(s):  
Nicola Milan ◽  
Paolo Parenti ◽  
Massimiliano Annoni ◽  
Marco Sorgato ◽  
Giovanni Lucchetta
Keyword(s):  
Surface Quality ◽  
Mass Production ◽  
Low Cost ◽  
Cutting Parameters ◽  
Process Chain ◽  
Grating Pattern ◽  
Mould Surface ◽  
Microstructured Surfaces ◽  
Blaze Grating ◽  
Plastic Parts

AbstractDiffractive microstructured surfaces are nowadays increasingly applied to polymeric parts for aesthetic, security and optical functionalities. However, both the machining of the mould blaze-grating and its replication on plastic are still representing challenging issues, from both the technical and economical points of view. In this work, an innovative process chain based on carbide tools micromilling of mould gratings was developed for mass production of diffractive patterns on injection moulded parts. A micromilling experimental campaign was conducted on a nickel-phosphorus (NiP) thick coating to machine a blaze-grating on the mould surface, evaluating the influence of the cutting parameters on the diffractive surface quality. Subsequently, the microstructures were replicated on ABS, PC and PMMA by injection moulding. The roughness parameters Sk, Spk and Svk were added with the idea that their sum is representative of the polymer replication of regular diffraction grating pattern. Moreover, the effect of the moulded grating surface quality on the optical performance was preliminarily assessed. The obtained results show that the proposed process chain is suitable for low-cost mass production of polymeric parts with diffractive microstructures.

Research Status of Subsequent Machining of Laser Cladding Layers

2020 ◽  
Vol 15 ◽  
Author(s):  
Lei Li ◽  
Yujun Cai ◽  
Guohe Li ◽  
Meng Liu
Keyword(s):  
Tool Wear ◽  
Surface Quality ◽  
Laser Cladding ◽  
Wear Surface ◽  
Chip Formation ◽  
Cutting Temperature ◽  
Dimensional Accuracy ◽  
Cutting Parameters ◽  
Cladding Layer ◽  
Cladding Layers

Background: As an important method of remanufacturing, laser cladding can be used to obtain the parts with specific shapes by stacking materials layer by layer. The formation mechanism of laser cladding determines the “Staircase effect”, which makes the surface quality can hardly meet the dimensional accuracy of the parts. Therefore, the subsequent machining must be performed to improve the dimensional accuracy and surface quality of cladding parts. Methods: In this paper, chip formation, cutting force, cutting temperature, tool wear, surface quality, and optimization of cutting parameters in the subsequent cutting of laser cladding layer are analyzed. Scholars have expounded and studied these five aspects but the cutting mechanism of laser cladding need further research. Results: The characteristics of cladding layer are similar to that of difficult to machine materials, and the change of parameters has a significant impact on the cutting performance. Conclusion: The research status of subsequent machining of cladding layers is summarized, mainly from the aspects of chip formation, cutting force, cutting temperature, tool wear, surface quality, and cutting parameters optimization. Besides, the existing problems and further developments of subsequent machining of cladding layers are pointed out. The efforts are helpful to promote the development and application of laser cladding remanufacturing technology.

A Study on the Birefringence Measurement in Injection Molded Parts Using Two Different Laser Sources and R-G-B Separation of White Light

2006 ◽  
Vol 326-328 ◽  
pp. 187-190
Author(s):  
Jong Sun Kim ◽  
Chul Jin Hwang ◽  
Kyung Hwan Yoon
Keyword(s):  
White Light ◽  
Low Cost ◽  
Main Idea ◽  
Injection Molding Process ◽  
Molding Process ◽  
Laser Method ◽  
High Productivity ◽  
Molded Parts ◽  
Injection Molded ◽  
Plastic Parts

Recently, injection molded plastic optical products are widely used in many fields, because injection molding process has advantages of low cost and high productivity. However, there remains residual birefringence and residual stresses originated from flow history and differential cooling. The present study focused on developing a technique to measure the birefringence in transparent injection-molded optical plastic parts using two methods as follows: (i) the two colored laser method, (ii) the R-G-B separation method of white light. The main idea of both methods came from the fact that more information can be obtained from the distribution of retardation caused by different wavelengths. The comparison between two methods is demonstrated for the same sample of which retardation is up to 850 nm.

scholarly journals Whispering Gallery Mode Based Optical Fiber Sensor for Measuring Concentration of Salt Solution

2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
Chia-Chin Chiang ◽  
Jian-Cin Chao
Keyword(s):  
Optical Fiber ◽  
Mass Production ◽  
Low Cost ◽  
Optical Fiber Sensor ◽  
Whispering Gallery Mode ◽  
Solution Concentration ◽  
Fiber Sensor ◽  
Average Sensitivity ◽  
Whispering Gallery ◽  
The Right

An optical fiber solution-concentration sensor based on whispering gallery mode (WGM) is proposed in this paper. The WGM solution-concentration sensors were used to measure salt solutions, in which the concentrations ranged from 1% to 25% and the wavelength drifted from the left to the right. The experimental results showed an average sensitivity of approximately 0.372 nm/% and anR2linearity of 0.8835. The proposed WGM sensors are of low cost, feasible for mass production, and durable for solution-concentration sensing.

Experimental investigation of the influence of cutting parameters on surface quality and on the special characteristics of micro-milled surfaces of hardened steels

2021 ◽  
pp. 095440622110130
Author(s):  
Barnabás Zoltán Balázs ◽  
Márton Takács
Keyword(s):  
Surface Quality ◽  
Surface Profile ◽  
Cutting Parameters ◽  
Relevant Information ◽  
Milling Process ◽  
Micro Milling ◽  
Machined Surface ◽  
Analysis Of Dynamics ◽  
Five Axis ◽  
Coated Carbide

Micro-milling is one of the most essential technologies to produce micro components, but due to the size effect, it has many special characteristics and challenges. The process can be characterised by strong vibrations, relatively large run-out and tool deformation, which directly affects the quality of the machined surface. This paper deals with a detailed investigation of the influence of cutting parameters on surface roughness and on the special characteristics of micro-milled surfaces. Several systematic series of experiments were carried out and analysed in detail. A five-axis micromachining centre and a two fluted, coated carbide micro-milling tool with a diameter of 500 µm were used for the tests. The experiments were conducted on AISI H13 hot-work tool steel and Böhler M303 martensitic corrosion resistance steel with a hardness of 50 HRC in order to gain relevant information of machining characteristics of potential materials of micro-injection moulding tools. The effect of the cutting parameters on the surface quality and on the ratio of Rz/ Ra was investigated in a comprehensive cutting parameter range. ANOVA was used for the statistical evaluation. A novel method is presented, which allows a detailed analysis of the surface profile and repetitions, and identify the frequencies that create the characteristic profile of the surface. The procedure establishes a connection between the frequencies obtained during the analysis of dynamics (forces, vibrations) of the micro-milling process and the characterising repetitions and frequencies of the surface.

scholarly journals Measuring the bore straightness during reaming with sensoric tools

2020 ◽  
Vol 14 (4) ◽  
pp. 535-544
Author(s):  
Andreas Bretz ◽  
Eberhard Abele ◽  
Matthias Weigold
Keyword(s):  
Mass Production ◽  
Cost Efficiency ◽  
Machine Tools ◽  
Processing Time ◽  
Process Chain ◽  
Machining Processes ◽  
High Quality ◽  
Random Samples ◽  
Hydraulic Valves ◽  
Productive Time

Abstract Reaming plays a crucial role in production to meet the high quality requirements of precision bore machining. It is either directly responsible for the final component quality or influences subsequent processes such as honing. The narrow tolerances are usually monitored by measuring random samples in mass production due to cost efficiency. Having a closer look at an exemplary process chain for the production of hydraulic valves shows the possibility to adapt the honing parameters which reduces processing time and costs. However, the bore straightness after the reaming process has to be known. In this paper an approach is presented which allows to record the bore straightness within the productive time. For this purpose, a sensory reaming system is developed. It can be used without additional components in the machine tool and thus integrated into existing machining processes. Cutting tests show that the system is able to measure the bore straightness as good as sensing probes used in machine tools.

scholarly journals Influence of cutting parameters on surface quality when machining a CoCrWNi alloy

2018 ◽  
Vol 178 ◽  
pp. 01009
Author(s):  
Manuela-Roxana Dijmărescu ◽  
Ioan-Cristian Tarbă ◽  
Maria-Cristina Dijmărescu ◽  
Vlad Gheorghiţă
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Surface Quality ◽  
Cutting Parameters ◽  
Medical Applications ◽  
Medical Implants

Due to their excellent biocompatibility and mechanical properties, the use of Co-Cr based alloys in medical applications has increased substantially. An important characteristic of the medical implants is their surface quality, this being a significant constraint when machining this kind of products. The aim of this paper is to present a research conducted in order to determine and expose the influence of turning cutting parameters on the surface roughness of a CoCrWNi alloy.

Surface Quality of Pulsed Laser Cutting of Difficult to Machine Steel

2011 ◽  
Vol 299-300 ◽  
pp. 1016-1019
Author(s):  
Tie Jun Li ◽  
Jing Tang ◽  
Li Jun Yan ◽  
Yang Wang
Keyword(s):  
Surface Quality ◽  
Laser Cutting ◽  
Pulsed Laser ◽  
Cutting Parameters ◽  
Quality Factors ◽  
Good Separation ◽  
Machine Steel ◽  
Optimum Cutting ◽  
Super Alloy

This paper presented the experiments of Nd:YAG pulsed laser cutting of titanium alloy, super-alloy and stainless steel sheet, and investigated the influences of different laser cutting parameters on the surface quality factors focusing surface morphology. In comparison with air-, argon- and nitrogen-assisted laser cutting, argon-assisted laser cutting comes with unaffected surface quality and is suitable for laser cutting with subsequent welding requirement. With analyzing the interaction between pulses overlapping rate and energy, the results show that medium pulse overlapping rate and lower pulse rate helps to improve the surface roughness with pulsed laser cutting. And the results would be beneficial to find optimum cutting parameters for good separation surface.

Study on Surface Roughness Based on Dynamic Minimum Thickness of Cut

2011 ◽  
Vol 88-89 ◽  
pp. 34-37
Author(s):  
Kuai Ji Cai
Keyword(s):  
Surface Roughness ◽  
Friction Coefficient ◽  
Atomic Force Microscope ◽  
Surface Quality ◽  
Experimental Verification ◽  
Cutting Parameters ◽  
Minimum Thickness ◽  
Atomic Force ◽  
Relationship Of ◽  
The Relationship

The relationship of the friction coefficient and the MTC were discussed, and the MTC and its effects on surface roughness were a theoretical analysised and experimental verification by AFM (atomic force microscope). The results show that the theoretical MTC tends to be minimal value then before the adhering effect to reach remarkable. Appropriate adjustments cutting parameters, the cutting process can always micro-cutting phase to reach the steady-thin chip, and no plowing phenomenon. So the surface residues highly were reduced and higher surface quality was achieved.

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