scholarly journals Experimental Study on the Effects of Coolants on Surface Quality and Mechanical Properties of Micromilled Thin-Walled Elgiloy

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1497 ◽  
Author(s):  
Da Qu ◽  
Peng Zhang ◽  
Jiadai Xue ◽  
Yun Fan ◽  
Zuhui Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Surface Quality ◽  
Lower Surface ◽  
Work Piece ◽  
Dry Machining ◽  
Core Component ◽  
The Core ◽  
Thin Walled ◽  
The One

In this study, minimum quantity coolant/lubrication (MQCL) is found to have significant impact on the surface quality and mechanical properties of the micromilled thin-walled work piece that is the core component of an aeroaccelerometer. Three kinds of coolants were used in the micromilling process to analyze their effects on surface quality and mechanical properties of the component. The experiment results show that an appropriate dynamic viscosity of coolant helps to improve surface roughness. The high evaporation rate of the coolants can enhance the cooling performance. Comparing with the dry machining case, MQCL has better performance on improving tool wear, surface quality, and mechanical properties of the micromilled work piece. It yielded up to 1.4–10.4% lower surface roughness compared with the dry machining case in this experiment. The machined work piece with the best mechanical properties and the one with the worst mechanical properties appeared in the ethyl alcohol and the dry machining case, respectively. The reasons for deteriorating surface quality and mechanical properties in dry machining cases are also analyzed. For improving the micromilling process, the penetration and cooling effect of the coolants are more important. This paper gives references to obtain better service performance of the component by improving the micromilling process.

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.

scholarly journals Surface roughness of edge glued panels (EGP) of amazon maneged species

2019 ◽  
Vol 43 ◽  
Author(s):  
Roberto Daniel de Araujo ◽  
Joaquim dos Santos ◽  
Claudete Catanhede do Nascimento ◽  
Cristiano Souza do Nascimento ◽  
Sâmia Valeria dos Santos Barros ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Sustainable Use ◽  
Lower Surface ◽  
Mechanical Tests ◽  
Important Criterion ◽  
Machining Performance ◽  
Technological Research ◽  
Tool Condition ◽  
Industrial Use

ABSTRACT In the Amazon, the sustainable use of wood is associated with technological research that indicates industrial use. Surface roughness of wood is an important criterion for assessing tool condition, machining performance and product quality. The objective of this study was to evaluate the surface roughness of five Amazonian woods used in the manufacture of EGP (Edge Glued Panels).The woods Angelim pedra, Angelim vermelho, Breu vermelho, Murici and Piãozinho, obtained from managed areas of the Amazon, were used in the manufacture of EGP panels. Surface treatments were performed with 120 and 180 grit sandpaper. Surface ripples (roughness) were measured using a digital roughness meter with needle (n = 180 readings). Physical and mechanical tests were performed on both wood and EGP samples, to verify the possible relationship between these properties and roughness. EGP Piãozinho presented better surface quality, which consists of lower roughness (lower surface wave height), while EGP Angelim pedra presented uneven surfaces. Surface quality was satisfactory when 120 grain sandpaper was applied to most products. The results showed a highly significant effect of roughness such as the physical-mechanical properties. The highlight of the study is the wood and EGP Piãozinho, because in all the tests, it always presented the best performances.

scholarly journals Impact of vapor polishing on surface quality and mechanical properties of extruded ABS

2018 ◽  
Vol 24 (2) ◽  
pp. 501-508 ◽  
Author(s):  
Clayton Neff ◽  
Matthew Trapuzzano ◽  
Nathan B. Crane
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Surface Quality ◽  
Complex Geometry ◽  
Substantial Impact ◽  
Solvent Vapor ◽  
Content Type ◽  
Minimal Impact ◽  
End Use ◽  
Traditional Manufacturing

Purpose Additive manufacturing (AM) is readily capable of producing models and prototypes of complex geometry and is advancing in creating functional parts. However, AM processes typically underperform traditional manufacturing methods in mechanical properties, surface roughness and hermeticity. Solvent vapor treatments (vapor polishing) are commonly used to improve surface quality in thermoplastic parts, but the results are poorly characterized. Design/methodology/approach This work quantifies the surface roughness change and also evaluates the effect on hermeticity and mechanical property impacts for “as-printed” and acetone vapor-polished ABS tensile specimens of 1-, 2- and 4-mm thicknesses produced by material extrusion (FDM). Findings Vapor polishing proves to decrease the power spectral density for surface roughness features larger than 20 µm by a factor of 10× and shows significant improvement in hermeticity based on both perfluorocarbon gross leak and pressure leak tests. However, there is minimal impact on mechanical properties with the thin specimens showing a slight increase in elongation at break but decreased elastic modulus. A bi-exponential diffusion decay model for solvent evaporation suggest a thickness-independent and thickness-dependent time constant with the latter supporting a plasticizing effect on mechanical properties. Originality/value The contributions of this work show vapor polishing can have a substantial impact on the performance for end-use application of ABS FDM components.

scholarly journals ПЕРСПЕКТИВЫ ПРИМЕНЕНИЯ АДДИТИВНЫХ ТЕХНОЛОГИЙ В АВИА- И РАКЕТОСТРОЕНИИ

2020 ◽  
pp. 59-65
Author(s):  
Сергей Викторович Аджамский ◽  
Анна Андреевна Кононенко ◽  
Ростислав Вячеславович Подольский
Keyword(s):  
Mechanical Properties ◽  
Lower Surface ◽  
Topological Optimization ◽  
Layer By Layer ◽  
Inclined Surfaces ◽  
Computer Based ◽  
Thin Walled ◽  
Traditional Manufacturing ◽  
Favorable Conditions ◽  
Automation Tools

SLM technology is an innovative production of products of complex geometric shapes through layer-by-layer material building-up based on a computer-based CAD model using special 3D printers. With the help of SLM technology, they create precise metal products for work as part of components and assemblies for critical purposes (for example, aerospace). SLM successfully replaces traditional manufacturing methods, since products built using SLM technology often surpass the properties of products made using traditional technologies.This technology has several advantages for the application and manufacture of aerospace products: the possible production of thin-walled parts, simplifying their production, by reducing the number of technological transitions, using computer programs and automation tools to optimize the product design, which opens up the possibility of reducing the weight of aircraft structural elements apparatuses.One of the opportunities that SLM technology allows to realize is the replacement of solid metal elements with openwork structures, ensuring a sufficient level of mechanical properties. The use of openwork designs and topological optimization can make it possible to lighten a part up to 50 %. However, it is important to ensure the necessary level of mechanical properties due to the reasonable design of elements: mesh thickness, cell size, and shape, etc. Besides, in aircraft and rocket science, often additive technologies are used to create products with internal channels of thin-walled products with inclined surfaces. Therefore, it is important to ensure the quality of thin-walled surfaces with different angles of inclination.Printing was carried out on a 3-D Alfa-150 printer manufactured by ALT Ukraine LLC. As part of the experiment, samples were made in the form of a cube with the internal structure of the honeycomb and a solid cube with equal dimensions in different modes. The second group of samples in the form of plates with different angles of inclination relative to the Z-axis (0°, 30°, 45°).When practicing printing modes with internal thin structures, it was found that under adverse conditions, fusion conditions were created, the metal fell through on a layer of powder, overhanging elements formed, and the lower surface with high roughness. Under favorable conditions, the lower surface is smooth, the layers are clearly defined, correspond to the given geometry of the model. An experiment was also performed to test the printing modes of flat samples with different angles of inclination. It has been established that different modes are optimal for different tilt angles. Thus, it was found that SLM technology allows you to create thin-section elements with maximum accuracy, and to produce parts with a unique geometric structure. According to the developed process parameters, parts of complex shape for operation in aerospace engineering can be created.

DECODING OF THE RELATION BETWEEN FRACTAL STRUCTURE OF CUTTING FORCE AND SURFACE ROUGHNESS OF MACHINED WORKPIECE IN END MILLING OPERATION

Fractals ◽  
2019 ◽  
Vol 27 (04) ◽  
pp. 1950054 ◽  
Author(s):  
HAMIDREZA NAMAZI ◽  
ALI AKHAVAN FARID ◽  
TECK SENG CHANG
Keyword(s):  
Surface Roughness ◽  
Cutting Force ◽  
Surface Quality ◽  
End Milling ◽  
Complex Structure ◽  
Dry Machining ◽  
End Mill ◽  
Milling Operation ◽  
Machining Operations

Analysis of the surface quality of workpiece is one of the major works in machining operations. Variations of cutting force is an important factor that highly affects the quality of machined workpiece during operation. Therefore, investigating about the variations of cutting forces is very important in machining operation. In this paper, we employ fractal analysis in order to investigate the relation between complex structure of cutting force and surface roughness of machined surface in end milling operation. We run the machining operation in different conditions in which cutting depths, type of cutting tool (serrated versus square end mills) and machining conditions (wet and dry machining) change. Based on the obtained results, we observed the relation between complexity of cutting force and surface roughness of generated surface of machined workpiece due to engagement with the flute surface of end mill, in case of using square end mill in dry machining condition, and also in case of using serrated end mill in wet machining condition. The fractal approach that was employed in this research can be potentially examined in case of other machining operations in order to investigate the possible relation between complex structure of cutting force and surface quality of machined workpiece.

In-Process Laser Re-Melting of Thin Walled Parts to Improve Surface Quality after Laser Metal Deposition

2019 ◽  
Vol 813 ◽  
pp. 191-196
Author(s):  
Francesco Bruzzo ◽  
Guendalina Catalano ◽  
Ali Gökhan Demir ◽  
Barbara Previtali
Keyword(s):  
Surface Roughness ◽  
Energy Density ◽  
Surface Quality ◽  
Metal Deposition ◽  
Laser Metal Deposition ◽  
Average Roughness ◽  
Thin Walls ◽  
Energy Inputs ◽  
Thin Walled

Laser metal deposition (LMD) is an additive manufacturing process highly adaptable to medium to large sized components with bulky structures as well as thin walls. Low surface quality of as-deposited LMD manufactured components with average roughness values (Ra) around 15-20μm is one of the main drawbacks that prevent the use of the part without the implementation of costly and time-consuming post-processes. In this work laser re-melting is applied right after LMD process with the use of the same equipment used for the deposition to treat AISI 316L thin walled parts. The surface quality improvement is assessed through the measurement of both areal surface roughness Sa(0.8mm) QUOTE and waviness Wa QUOTE (0.8mm) parameters. Moreover, roughness power spectrum is used to point out the presence of principal periodical components both in the as-deposited and in the re-melted surfaces. Then, the transfer function is calculated to better understand the effects of laser re-melting on the topography evolution, measuring the changes of individual components contributing to the surface roughness such as the layering technique and the presence of sintered particles. Experiments showed that while low energy density inputs are not capable to properly modify the additive surface topography, excessive energy inputs impose a strong periodical component with wavelength equal to the laser scan spacing and directionality determined by the used strategy. When a proper amount of energy density input is used, laser re-melting is capable to generate smooth isotropic topographies without visible periodical surface structures.

scholarly journals Novel Bicomponent Functional Fibers with Sheath/Core Configuration Containing Intumescent Flame-Retardants for Textile Applications

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3095 ◽  
Author(s):  
Muhammad Maqsood ◽  
Gunnar Seide
Keyword(s):  
Mechanical Properties ◽  
Flame Retardants ◽  
Woven Fabric ◽  
Core Component ◽  
Cone Calorimetry ◽  
Limiting Oxygen Index ◽  
Bicomponent Fibers ◽  
The Core ◽  
Melt Spun ◽  
Intumescent Flame Retardants

The objective of this study is to examine the effect of intumescent flame-retardants (IFR’s) on the spinnability of sheath/core bicomponent melt-spun fibers, produced from Polylactic acid (PLA) single polymer composites, as IFR’s have not been tested in bicomponent fibers so far. Highly crystalline PLA-containing IFR’s was used in the core component, while an amorphous PLA was tested in the sheath component of melt-spun bicomponent fibers. Ammonium polyphosphate and lignin powder were used as acid, and carbon source, respectively, together with PES as a plasticizing agent in the core component of bicomponent fibers. Multifilament fibers, with sheath/core configurations, were produced on a pilot-scale melt spinning machine, and the changes in fibers mechanical properties and crystallinity were recorded in response to varying process parameters. The crystallinity of the bicomponent fibers was studied by differential scanning calorimetry and thermal stabilities were analyzed by thermogravimetric analysis. Thermally bonded, non-woven fabric samples, from as prepared bicomponent fibers, were produced and their fire properties, such as limiting oxygen index and cone calorimetry values were measured. However, the ignitability of fabric samples was tested by a single-flame source test. Cone calorimetry showed a 46% decline in the heat release rate of nonwovens, produced from FR PLA bicomponent fibers, compared to pure PLA nonwovens. This indicated the development of an intumescent char by leaving a residual mass of 34% relative to the initial mass of the sample. It was found that the IFRs can be melt spun into bicomponent fibers by sheath/core configuration, and the enhanced functionality in the fibers can be achieved with suitable mechanical properties.

scholarly journals The peculiar radio structure of quasar 1320+299

1986 ◽  
Vol 119 ◽  
pp. 191-192
Author(s):  
T.J. Cornwell ◽  
D.J. Saikia ◽  
P. Shastri ◽  
L. Feretti ◽  
G. Giovannini ◽  
...  
Keyword(s):  
Radio Source ◽  
Linear Size ◽  
Core Component ◽  
Radio Structure ◽  
The Core ◽  
The One

The radio source B2 1320+299 is associated with a 20m QSO. Apart from the core component, it has two outer components on the same side of the QSO; it was therefore classified as of the one-sided (‘D2’) type. The radio structure is unusual in that the three slightly non-collinear components are apparently unconnected and the projected linear size for any plausible redshift is large for a ‘D2’ source (Feretti et al. 1982, Astron. Astrophys.115, 423). The radio structure has now been mapped with the VLA (λ20 & 6 cm, B array and λ20, 6 & 2 cm, A array; Figs.1a, b).

Curved-layered material extrusion modeling for thin-walled parts by a 5-axis machine

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Xiaojing Feng ◽  
Bin Cui ◽  
Yaxiong Liu ◽  
Lianggang Li ◽  
Xiaojun Shi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Additive Manufacturing ◽  
Layered Material ◽  
Bottom Surface ◽  
Motion Mechanism ◽  
Content Type ◽  
Material Extrusion ◽  
Thin Walled ◽  
Five Axis

Purpose The purpose of this paper is to solve the problems of poor mechanical properties, high surface roughness and waste support materials of thin-walled parts fabricated by flat-layered additive manufacturing process. Design/methodology/approach This paper proposes a curved-layered material extrusion modeling process with a five-axis motion mechanism. This process has advantages of the platform rotating, non-support printing and three-dimensional printing path. First, the authors present a curved-layered algorithm by offsetting the bottom surface into a series of conformal surfaces and a toolpath generation algorithm based on the geodesic distance field in each conformal surface. Second, they introduce a parallel five-axis printing machine consisting of a printing head fixed on a delta-type manipulator and a rotary platform on a spherical parallel machine. Findings Mechanical experiments show the failure force of the five-axis printed samples is 153% higher than that of the three-axis printed samples. Forming experiments show that the surface roughness significantly decreases from 42.09 to 18.31 µm, and in addition, the material consumption reduces by 42.90%. These data indicate the curved-layered algorithm and five-axis motion mechanism in this paper could effectively improve mechanical properties and the surface roughness of thin-walled parts, and realize non-support printing. These methods also have reference value for other additive manufacturing processes. Originality/value Previous researchers mostly focus on printing simple shapes such as arch or “T”-like shape. In contrast, this study sets out to explore the algorithm and benefits of modeling thin-walled parts by a five-axis machine. Several validated models would allow comparability in five-axis printing.

The Surface Quality Detection and Electrical Discharge Mirror Machining with Non-Mixed-Powder

2015 ◽  
Vol 775 ◽  
pp. 214-218
Author(s):  
Yuan Lin ◽  
Hao Jiang ◽  
Huan Ran Lv ◽  
Xiu Wu Sui
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Electrical Discharge ◽  
Measuring Method ◽  
Work Piece ◽  
Analysis Method ◽  
Element Analysis ◽  
Mixed Powder ◽  
Quality Detection ◽  
The Impact

By using analytical and finite element analysis method, this paper analyzes the various factors on the impact of EDM surface roughness, puts forward a new mirror machining method of changing the order of the processing conditions and increasing the momentum of the swinging electrode in the process of EDM. Puts a measuring method for the surface quality with white light interferometer characterized by non-contact, high precision and vertical resolution in nanometer. Experiments show that in the non-mixed powder fluid, without replacing the electrodes and the processed work-piece is 45 # steel, the surface roughness of work-piece is 0.02 micro-meter, which meets the requirements for precision of the electrical discharge mirror machining.

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