Development of Jig for Sintering Hollow Tube Mat

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.761.631 ◽

2015 ◽

Vol 761 ◽

pp. 631-635

Author(s):

Abu Bakar Mohd Hadzley ◽

R. Izamshah ◽

Mohd Amran ◽

W. Azahar

Keyword(s):

Honeycomb Structure ◽

Clamping Force ◽

Sintering Process ◽

Plastic Parts ◽

Sufficient Strength ◽

Molten Region

This paper presents the development of a jig for sintering a hollow tube mat. The jig consisted of metal frames, clampers, rails and wheels that were assembled together to hold a stack of hollow tubes in a form of a honeycomb structure. The sintering process involved a large oven where the hollow tube was sintered up to 120°C within two hours. During the sintering process, a partial of plastic parts was melted to allow diffusion around the particle cores. A clamping force from the jig held the tubes to make sure that the molten region around the sintered tubes retained in contact. This gives the compact a sufficient strength to hold together as the heat was removed. The jig developed in this study was capable to produce a hollow cellular mat within the size of approximately 1m (width) x 1m (length) x 1m (height).

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The Impact of Employing Different Quality PA2200 Powder Grades to Shrinkage on Sintered Part in Selective Laser Sintering Process

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.789-790.126 ◽

2015 ◽

Vol 789-790 ◽

pp. 126-130

Author(s):

W.A.Y. Yusoff ◽

D.T. Pham ◽

K.D. Dotchev

Keyword(s):

Selective Laser Sintering ◽

Laser Sintering ◽

Sintering Process ◽

Melt Flow Rate ◽

Input Material ◽

Low Degree ◽

Powder Properties ◽

Plastic Parts ◽

The Impact

One of the challenges which Laser Sintering faces is the Rapid Manufacturing of plastic parts with good consistent quality. This is due to the fact that plastic powder properties deteriorate during the long periods of time through the LS building and cooling cycles. This paper presents an experimental study of the deterioration or ageing of PA12 powder properties in the LS process. The influences of different grades of recycled PA12 powders are investigated. The main aim of this research is to develop a methodology of controlling the input material properties that will ensure consistent and good quality of the fabricated parts. From the experiment it was found that PA12 powder with high melt flow rate, low melting temperature, low glass transition temperature and low degree of crystallization temperature could improve the sintering process to produce a good Laser Sintering (LS) parts with lower shrinkage rate.

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Custom-Made Titanium Mesh Tray for Mandibular Reconstruction Using an Electron Beam Melting System

Materials ◽

10.3390/ma14216556 ◽

2021 ◽

Vol 14 (21) ◽

pp. 6556

Author(s):

Isao Hoshi ◽

Tadashi Kawai ◽

Shingo Kurosu ◽

Tadaharu Minamino ◽

Kei Onodera ◽

...

Keyword(s):

Electron Beam ◽

Mechanical Strength ◽

Electron Beam Melting ◽

Maxillofacial Surgery ◽

Honeycomb Structure ◽

Mandibular Reconstruction ◽

Titanium Mesh ◽

Custom Made ◽

Computer Aided ◽

Sufficient Strength

Mandibular reconstruction using a titanium mesh tray and autologous bone is a common procedure in oral and maxillofacial surgery. However, there can be material problems—such as broken titanium mesh trays—which may undermine long-term functionality. This study was designed to investigate the optimal conditions for a titanium mesh tray with an ideal mandibular shape and sufficient strength, using computer-aided design, computer-aided manufacturing technology, and electron beam additive manufacturing. Specimens were prepared using Ti-6Al-4V extra low interstitial titanium alloy powder and an electron beam melting (EBM) system. The mechanical strength of the plate-shaped specimens was examined for differences in the stretch direction with respect to the stacking direction and the presence or absence of surface treatment. While evaluating the mechanical strength of the tray-shaped specimens, the topology was optimized and specimens with a honeycomb structure were also verified. Excellent mechanical strength was observed under the condition that the specimen was stretched vertically in the stacking direction and the surface was treated. The results of the tray-shaped specimens indicated that the thickness was 1.2 mm, the weight reduction rate was 20%, and the addition of a honeycomb structure could withstand an assumed bite force of 2000 N. This study suggests that the EBM system could be a useful technique for preparing custom-made titanium mesh trays of sufficient strength for mandibular reconstruction by arranging various manufacturing conditions.

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Novel Shrinkage-Free Structural Ceramic Materials for Gas Turbine Applications

Volume 1: Aircraft Engine; Ceramics; Coal, Biomass and Alternative Fuels; Manufacturing, Materials and Metallurgy; Microturbines and Small Turbomachinery ◽

10.1115/gt2008-50549 ◽

2008 ◽

Author(s):

A. V. Soudarev ◽

V. G. Konakov ◽

N. F. Morozov ◽

I. A. Ovidko ◽

B. N. Semenov

Keyword(s):

Metal Cutting ◽

Cutting Tools ◽

Ceramic Materials ◽

Diffusion Welding ◽

Treatment Technique ◽

The Novel ◽

Sintering Process ◽

Electrically Conductive ◽

Sufficient Strength ◽

Ceramic Blank

The paper presents results of development of the novel shrinkage-free, adaptable to machining and easily welded alumo-boron-carbide silicon materials that experience the cermet stage during their manufacturing. A specific feature of the like ceramics is their double-stage sintering process when, after the original stage, a metal-ceramic blank has a sufficient strength and is easily machined by conventional metal-cutting tools. In addition, such materials are electrically conductive, therefore, the elasto-erosion treatment technique can be applied. Subsequently, a machined part is finally sintered, whereas all the geometries remain actually unchanged due to the shrinkage absence. Prior to the final sintering, all separate parts can be joined by the diffusion welding with the seam strength being 5–10% different from the strength of the main part. The paper provides an insight into the processes and results of tests of the representative selections of samples of four types of the structural ceramics that are experiencing the cermet stage during the process of their formation. Also, ceramic parts for the CGTE hot passage are demonstrated.

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Review on Development of Ceramic Membrane From Sol-Gel Route: Parameters Affecting Characteristics of the Membrane

IIUM Engineering Journal ◽

10.31436/iiumej.v1i2.334 ◽

1970 ◽

Vol 1 (2) ◽

Author(s):

M. R. Othman and H. Mukhtar

Keyword(s):

Ceramic Membrane ◽

Sol Gel ◽

Gas Permeation ◽

Inorganic Membrane ◽

Drying Rate ◽

Membrane Thickness ◽

Sintering Process ◽

Gel Technique ◽

Membrane Development ◽

Sufficient Strength

The importance of laboratory scale ceramic membrane preparation using sol-gel technique with pore sizes in the range of 1-10nm is reviewed. Parameters affecting the characteristics of membrane during membrane development are highlighted and discussed in detail. Experimental results from literatures have shown that the correct amount of acid, water, PVA, appropriate membrane thickness, proper control of drying rate, and appropriate temperature profile selection during sintering process are necessary in order to acquire sufficient strength and reduce the formation of crack in the membrane. The different temperature setting during sintering process also influences the size of pore formed.Key Words: Sol-Gel, Inorganic Membrane, Ceramic Membrane, Gas Permeation, Sintering, Sol Properties, Membrane Morphologies, Pore Size Distribution.

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The Development of Small Size Double Side Metal Plate with Internal Structure Utilizing Metal Injection Molding Process

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.365-366.1132 ◽

2013 ◽

Vol 365-366 ◽

pp. 1132-1135

Author(s):

Kwang Ho Shin ◽

Young Moo Heo ◽

Jong Deok Kim

Keyword(s):

Injection Molding ◽

Internal Structure ◽

Steel Powder ◽

Honeycomb Structure ◽

Metal Plate ◽

Metal Injection Molding ◽

Injection Molding Process ◽

Sintering Process ◽

Molding Process ◽

Plastic Injection

In this study, it is focused to make a double side metal plate with internal structure. The stainless steel powder (17-4PH 15F) was used in PIM process. PE(HDPE and LDPE) and PP were used to make the sacrificed insert with honeycomb structure using plastic injection molding process. And then these sacrificed insert parts were inserted at metal injection mold and metal injection molding process was carried out to build green part with rectangular shape. Subsequently, de-binding and sintering process were adopted. The dimensional contraction was occurred about 15.5% in width direction and about 16.2% in thickness direction.

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Microstructural Study of Diamond Deformed Under High Pressure and Temperature

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100118072 ◽

1985 ◽

Vol 43 ◽

pp. 230-231

Author(s):

E. F. Koch

Keyword(s):

High Pressure ◽

High Temperature ◽

Lattice Structure ◽

Diamond Particle ◽

Polycrystalline Diamond ◽

Sintering Process ◽

Ion Milling ◽

Sintered Compact ◽

Transmission Electron ◽

High Pressure Sintering

Because of the extremely rigid lattice structure of diamond, generating new dislocations or moving existing dislocations in diamond by applying mechanical stress at ambient temperature is very difficult. Analysis of portions of diamonds deformed under bending stress at elevated temperature has shown that diamond deforms plastically under suitable conditions and that its primary slip systems are on the ﹛111﹜ planes. Plastic deformation in diamond is more commonly observed during the high temperature - high pressure sintering process used to make diamond compacts. The pressure and temperature conditions in the sintering presses are sufficiently high that many diamond grains in the sintered compact show deformed microtructures.In this report commercially available polycrystalline diamond discs for rock cutting applications were analyzed to study the deformation substructures in the diamond grains using transmission electron microscopy. An individual diamond particle can be plastically deformed in a high pressure apparatus at high temperature, but it is nearly impossible to prepare such a particle for TEM observation, since any medium in which the diamond is mounted wears away faster than the diamond during ion milling and the diamond is lost.

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Morphologic alteration in the muscles of patients with hypokalemic periodic paralysis or myopathy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100158650 ◽

1990 ◽

Vol 48 (3) ◽

pp. 222-223

Author(s):

T. Shimizu ◽

Y. Muranaka ◽

I. Ohta ◽

N. Honda

Keyword(s):

Clinical Manifestations ◽

Quadriceps Muscle ◽

Honeycomb Structure ◽

Periodic Paralysis ◽

Ultrastructural Changes ◽

Hypokalemic Periodic Paralysis ◽

Electron Microscopic ◽

Tubular Aggregates ◽

Hypokalemic Myopathy ◽

Transmission Electron

There have been many reports on ultrastructural alterations in muscles of hypokalemic periodic paralysis (hpp) and hypokalemic myopathy(hm). It is stressed in those reports that tubular structures such as tubular aggregates are usually to be found in hpp as a characteristic feature, but not in hm. We analyzed the histological differences between hpp and hm, comparing their clinical manifestations and morphologic changes in muscles. Materials analyzed were biopsied muscles from 18 patients which showed muscular symptoms due to hypokalemia. The muscle specimens were obtained by means of biopsy from quadriceps muscle and fixed with 2% glutaraldehyde (pH 7.4) and analyzed by ordinary method and modified Golgimethod. The ultrathin section were examined in JEOL 200CX transmission electron microscopy.Electron microscopic examinations disclosed dilated t-system and terminal cistern of sarcoplasmic reticulum (SR)(Fig 1), and an unique structure like “sixad” was occasionally observed in some specimens (Fig 2). Tubular aggregates (Fig 3) and honeycomb structure (Fig 4) were also common characteristic structures in all cases. These ultrastructural changes were common in both the hypokalemic periodic paralysis and the hypokalemic myopathy, regardless of the time of biopsy or the duration of hypokalemia suffered.

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Crushing performances of Kirigami modified honeycomb structure in three axial directions

Thin-Walled Structures ◽

10.1016/j.tws.2020.107365 ◽

2021 ◽

Vol 160 ◽

pp. 107365

Author(s):

Zhejian Li ◽

Qiusong Yang ◽

Rui Fang ◽

Wensu Chen ◽

Hong Hao

Keyword(s):

Honeycomb Structure

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Sun Load Analysis and Testing on Automotive Front Lighting Products

Light & Engineering ◽

10.33383/2019-026 ◽

2020 ◽

pp. 116-122

Author(s):

Emre Öztürk ◽

Mehmet Aktaş ◽

Tunç Şenyüz

Keyword(s):

Prolonged Exposure ◽

Hot Spot ◽

Load Test ◽

Angle Of Incidence ◽

The Sun ◽

Solar Simulator ◽

Automotive Lighting ◽

Inclination Angles ◽

Plastic Parts ◽

Load Simulation

The purpose of this research is to reach good correlation between sun load simulation and solar focusing test for exterior automotive lighting products. Light coming from sun is highly collimated (parallel rays) and focusable from lenses with concave structure. Focusing incidence leads to a hot spot on lens surrounding plastic parts which may cause melting failures at high temperature zones. Sun load simulation is performing to eliminate risk of discoloration, deformation, out gassing, coating failures and fire with prolonged exposure from field. Irradiance values in W/m2 defined in simulation as heat source depending of an angle of incidence of the sun radiation. At first step, simulation is performing with 5 degree intervals to define the critical zones then intervals decreased to 2 degree to detect the critical azimuth and inclination angles. Critical azimuth and inclination angles is checking with ray trace analysis to check the bouncing of sun rays and possible solution to eliminate focuses with design solutions. After numerical analysis to release and validate the automotive lighting products regarding the sun load test, measurement with first parts is necessary. Measurement is performing for all critical angles which have been detected at simulation with thermal camera under ultra high-collimation solar simulator. Measured temperatures are settled according to environment conditions and correlation is checking with simulations.

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