Effect of Space Holder Size on the Porous High Purity Aluminum Property

2020 ◽  
Vol 846 ◽  
pp. 93-98
Author(s):  
Sunisa Khamsuk ◽  
K. Choosakull ◽  
P. Wanwong

Porous high purity aluminum was fabricated using a powder metallurgy route combined with the space holder technique. The high purity aluminum powder was mixed with three different particle sizes and contents of the space holder material. The mixed powders were cold compacted at 400 MPa and sintered at 550 °C. The effects of space holder size on the microstructure and mechanical properties of porous high purity aluminum were systematically studied. Results revealed that the size and content of the space holder materials have a significant effect on the mechanical properties of porous aluminium. The compressive strength and hardness of the porous aluminum increased as the size and amount of the space holder material increased and decreased, respectively. The thickness of the cell wall increased with an increase particle size of the space holder material.

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2303
Author(s):  
Congyu Zhong ◽  
Liwen Cao ◽  
Jishi Geng ◽  
Zhihao Jiang ◽  
Shuai Zhang

Because of its weak cementation and abundant pores and cracks, it is difficult to obtain suitable samples of tectonic coal to test its mechanical properties. Therefore, the research and development of coalbed methane drilling and mining technology are restricted. In this study, tectonic coal samples are remodeled with different particle sizes to test the mechanical parameters and loading resistivity. The research results show that the particle size and gradation of tectonic coal significantly impact its uniaxial compressive strength and elastic modulus and affect changes in resistivity. As the converted particle size increases, the uniaxial compressive strength and elastic modulus decrease first and then tend to remain unchanged. The strength of the single-particle gradation coal sample decreases from 0.867 to 0.433 MPa and the elastic modulus decreases from 59.28 to 41.63 MPa with increasing particle size. The change in resistivity of the coal sample increases with increasing particle size, and the degree of resistivity variation decreases during the coal sample failure stage. In composite-particle gradation, the proportion of fine particles in the tectonic coal sample increases from 33% to 80%. Its strength and elastic modulus increase from 0.996 to 1.31 MPa and 83.96 to 125.4 MPa, respectively, and the resistivity change degree decreases. The proportion of medium particles or coarse particles increases, and the sample strength, elastic modulus, and resistivity changes all decrease.


2021 ◽  
Vol 10 (2) ◽  
pp. 48-52
Author(s):  
Cut Rizka Maulida ◽  
Mursal Mursal ◽  
Ismail Ismail

Abstrak. Penelitian ini bertujuan untuk membuat papan partikel dengan menggunakan limbah ampas kopi dan resin epoksi sebagai perekat. Komposisi resin epoksi divariasikan yaitu 5, 10, 15 dan 20 vol.% untuk masing-masing partikel ampas kopi berukuran 20 dan 40 mesh. Papan partikel dibuat dengan teknik pressing dengan beban sebesar 9 ton selama 30 menit. Sifat mekanik yang diuji adalah MOE, MOR, dan kuat tekan. Sifat fisis papan partikel yang diuji adalah kerapatan dan pengembangan tebal. Hasil menunjukkan bahwa nilai MOE tertinggi yaitu 20,910 kgf/cm2 pada komposisi 95 vol.% ampas kopi dan 5 vol.% resin epoksi dengan ukuran ampas kopi 40 mesh. MOR tertinggi yaitu 167 kgf/cm2 pada ukuran partikel 40 mesh dengan komposisi ampas kopi 90 vol.% dan resin epoksi 10 vol.%. Nilai kuat tekan tertinggi diperoleh 220 kgf/cm2 pada 20 mesh, dengan komposisi 85 vol.% ampas kopi dan 15 vol.% resin epoksi. Kerapatan dan pengembangan tebal papan partikel yang tertinggi masing-masing adalah 1,16 g/cm3 dan 0,85%. Secara umum, sifat mekanis papan partikel ampas kopi tergantung pada komposisi dan ukuran partikel ampas kopi. Namun, sifat fisisnya tidak berubah secara signifikan untuk ukuran partikel dan komposisi yang berbeda. Papan partikel yang diperoleh dari penelitian ini memenuhi standar ANSI sehingga berpotensi untuk dijadikan sebagai papan partikel atau komposit. Abstract.. This study aims to make a particle board using coffee ground waste and epoxy resin as an adhesive. The composition of the epoxy resin was varied, namely 5, 10, 15 and 20 vol.% for 20 mesh and 40 mesh of coffee grounds particles. Particle board is made by pressing technique with a load of 9 tons for 30 minutes. The mechanical properties tested were MOE, MOR, and compressive strength. The physical properties of the particle board tested were density and thickness swelling. The results showed that the highest MOE particle board was 20.910 kgf/cm2 (95 vol.% coffee grounds:5 vol.% epoxy resin; 40 mesh). The highest MOR was 167 kgf/cm2 (90 vol.% coffee grounds:10 vol.% epoxy resin;40 mesh). The hihgest compressive strength values was 220 kgf/cm2 (85 vol.% coffee grounds:15 vol.% epoxy resin;20 mesh). The highest density and thickness expansion were 1.16 g/cm3 and 0.85%, respectively. In general, the mechanical properties of coffee grounds particleboard depend on the composition and particle size of coffee grounds. However, their physical properties do not change significantly for different particle sizes and compositions. The particle board obtained from this study meets the standard of ANSI. Thus, coffee grounds have the potential to be used as particle board or composite. Keywords particle board, coffee grounds, epoxy resin, mechanical properties, physical properties


Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6813
Author(s):  
Yingdi Liao ◽  
Hongyi Shi ◽  
Shimin Zhang ◽  
Bo Da ◽  
Da Chen

In order to solve the problem of lack of natural river sand, crushed waste oyster shells (WOS) were used to replace river sand. By replacing 20% river sand, WOS mortar with different particle sizes of WOS were made for the experiment. Through experimental observation, the initial slump and slump flow loss rate were studied. The effects of different particle sizes and curing times on the compressive strength, flexural strength, static elastic modulus, and dry shrinkage of WOS mortar were analyzed. The relationship formulas between the compressive strength, flexural strength, particle size, and curing age were proposed. The results showed that the setting time and slump flow decreased with a decrease in the particle size of WOS. It was also found that the mortar with fine crushed WOS had high compressive strength, flexural strength, and static elastic modulus at both early and long-term curing age. A formula was proposed to describe the development of the compressive strength with the particle size of WOS and curing time, and the relations among these mechanical properties were discussed. Furthermore, drying shrinkage increased when WOS was used and could not satisfy the standard requirement of 0.075%. In contrast, the addition of fine WOS and double-dose sulfonated naphthalene-formaldehyde superplasticizer (SNF SP) reduced the shrinkage rate of the mortar by 8.35% and provided better workability and mechanical properties for mortar.


2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Punnaman Norrarat ◽  
Weerachart Tangchirapat ◽  
Smith Songpiriyakij ◽  
Chai Jaturapitakkul

This paper investigates the cement hydration, and the slag reaction contributes to the compressive strengths of mortars mixed with ground river sand (GRS) and ground-granulated blast furnace (GGBF) slag with different particle sizes. GRS (inert material) and GGBF slag (reactive material) were ground separately until the median particle sizes of 32 ± 1, 18 ± 1, and 5 ± 1 micron and used to replace Portland cement (PC) in large amount (40–60%) by weight of the binder. The results showed that, at the early age, the compressive strength obtained from the cement hydration was higher than that obtained from the slag reaction. The results of compressive strength also indicated that the GGBF slag content and particle size play important roles in the slag reaction at the later ages, whereas cement hydration is more prominent at the early ages. Although the results could be expected from the use of GGBF slag to replace PC in mortar or concrete, this study had presented the values of the compressive strength along with ages and the finenesses of GGBF slag that contributed from cement hydration and from GGBF slag reaction.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Liliana Ávila Córdoba ◽  
Gonzalo Martínez-Barrera ◽  
Carlos Barrera Díaz ◽  
Fernando Ureña Nuñez ◽  
Alejandro Loza Yañez

Concretes consisting of portland cement (OPC), silica sand, gravel, water, and recycled PET particles were developed. Specimens without PET particles were prepared for comparison. Curing times, PET particle sizes, and aggregate concentrations were varied. The compressive strength, compressive strain at yield point, and Young modulus were determined. Morphological and chemical compositions of recycled PET particles were seen in a scanning electron microscopy. Results show that smaller PET particle sizes in lower concentrations generate improvements on compressive strength and strain, and Young’s modulus decreases when the size of PET particles used was increased.


2017 ◽  
Vol 863 ◽  
pp. 26-32
Author(s):  
Ming Zhou Su ◽  
Hui Meng Wang ◽  
Chang Chen

Porous irons with only micropores were produced through powder metallurgy route. Corn starch of small particle size (5-15μm) was utilized to regulate the densification of green compacts. The structural and mechanical properties of porous irons sintered at different temperatures were evaluated. The porosities increased with increasing the starch content, which reduced compressive strength and increased volumetric shrinkage. The compressive yield stress increased with increasing sintering temperature. It was also found that the effect of sintering temperature on the microstructure and compressive properties was more obvious when green compacts were less densified. Moreover, volumetric shrinkage of porous irons without adding starch remains in a quite low level for different sintering temperatures.


2014 ◽  
Vol 1000 ◽  
pp. 277-280 ◽  
Author(s):  
Pavel Šiler ◽  
Ondřej Bezděk ◽  
Iva Kolářová ◽  
Eva Bartoníčková ◽  
Tomáš Opravil ◽  
...  

This work is focused on the influence of aggregates on the mechanical properties of concrete and hydration process. The flexural strength and compressive strength were observed after 1, 7 and 28 days of curing. The process of hydration was monitored using isoperibolic calorimetry. Laser particle size analysis of aggregates was also performed. The following materials were used: Portland cement CEM I 42,5 R-Sc, finely ground silica sand, calcinated bauxite, fine, medium and rough testing sand (defined in ČSN EN 196-1).


2011 ◽  
Vol 284-286 ◽  
pp. 984-988
Author(s):  
An Shun Cheng ◽  
Yue Lin Huang ◽  
Chung Ho Huang ◽  
Tsong Yen

The study aims to research the effect of the particle size of fly ash on the compressive strength and fracture toughness of high performance concrete (HPC). In all HPC mixtures, the water-to-binder ratio selected is 0.35; the cement replacement ratios includes 0%, 10% and 20%; the particle sizes of fly ash have three types of passing through sieves No. 175, No. 250 and No. 325. Three-point-bending test was adopted to measure the load-deflection relations and the maximum loads to determine the fracture energy (GF) and the critical stress intensity factor (KSIC). Test results show that adding fly ash in HPC apparently enhances the late age strengths of HPC either for replacement ratio of 10% or 20%, in which the concrete with 10% fly ash shows the higher effect. In addition, the smaller the particle size is the better the late age concrete strength will be. The HPC with the finer fly ash can have higher strength development and the values of GF and KSIC due to the facts of better filling effect and pozzolanic reaction. At late age, the GF and KSIC values of concrete with 10% fly ash are all higher than those with 20% fly ash.


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