Wet erosion damage of Cr3C2/Al2O3 composite

2003 ◽  
Vol 18 (5) ◽  
pp. 1162-1167
Author(s):  
Ching-An Jeng ◽  
Jow-Lay Huang
Keyword(s):  
Thermal Expansion Mismatch ◽  
Sintering Process ◽  
Test Rig ◽  
Erosion Damage ◽  
Erosion Mechanism ◽  
Al2o3 Composite ◽  
Erosion Test ◽  
Injection Molded ◽  
Triple Points

This study focused on investigating the role of interfacial microcracking of injection-molded Cr3C2/Al2O3 composite on the erosion mechanism under an impingement erosion test rig. The surface residual strain (stresses) as well as damage were compared in both airborne and wet erosion. The delays in crack propagation at interfacial or triple points and the crack direction changes were frequently observed in the composite. Spontaneous microcracking induced from sintering process, due to thermal expansion mismatch between alumina and chromium carbide, played a key role in erosion mechanism.

Investigation of Microstructure and Property of Fe3Al/Al2O3 Composites

2010 ◽  
Vol 150-151 ◽  
pp. 1409-1412 ◽  
Author(s):  
Tao Jiang
Keyword(s):  
Heat Treatment ◽  
Phase Composition ◽  
Mechanical Alloying ◽  
Sintering Process ◽  
Composite Powders ◽  
Al2o3 Composite ◽  
Al2o3 Phase ◽  
The Mean ◽  
Xrd Patterns ◽  
Al2o3 Matrix

The Fe3Al/Al2O3 composites were fabricated by pressureless sintering process. The Fe3Al intermetallics compounds powders were fabricated by mechanical alloying and heat treatment, then the Fe3Al powders and Al2O3 powders were mixed and the Fe3Al/Al2O3 composite powders were prepared, so the Fe3Al/Al2O3 composites were fabricated by sintering process at 1700oC for 2h. The phase composition and microstructure of Fe3Al intermetallics compounds powders produced by mechanical alloying and heat treatment were investigated. The phase composition, microstructure and mechanical properties of the Fe3Al/Al2O3 composites sintered bulks were investigated. The XRD patterns results showed that there existed Fe3Al phase and Al2O3 phase in the sintered composites. The Fe3Al/Al2O3 composites sintered bulks exhibited the homogenous and compact microstructure, the Fe3Al particles were homogenously distributed in the Al2O3 matrix, the mean particles size of Fe3Al intermetallics was about 3-5μm. The Fe3Al/Al2O3 composites exhibited more homogenous and compact microstructure with the increase of Fe3Al content in the Al2O3 matrix. The density and relative density of the Fe3Al/Al2O3 composites increased gradually with the increase of Fe3Al content. The fracture strength and fracture toughness of the Fe3Al/Al2O3 composites increased gradually with the increase of Fe3Al content. The elastic modulus and hardness (HRA) of the Fe3Al/Al2O3 composites decreased gradually with the increase of Fe3Al content.

The role of pseudomorphic structure in sintering process

2021 ◽  
pp. 130307
Author(s):  
Jiuhong Ma ◽  
Huizhong Zhao ◽  
Han Zhang ◽  
Yang Yang ◽  
Yichong Li ◽  
...  
Keyword(s):  
Sintering Process

scholarly journals Role of Sintering Temperature in Production of Nepheline Ceramics-Based Geopolymer with Addition of Ultra-High Molecular Weight Polyethylene

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1077
Author(s):  
Romisuhani Ahmad ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Wan Mastura Wan Ibrahim ◽  
Kamarudin Hussin ◽  
Fakhryna Hannanee Ahmad Zaidi ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Sintering Temperature ◽  
Ceramic Materials ◽  
Microstructural Properties ◽  
Sintering Process ◽  
Final Microstructure ◽  
Change Of Microstructure ◽  
Ultra High Molecular Weight

The primary motivation of developing ceramic materials using geopolymer method is to minimize the reliance on high sintering temperatures. The ultra-high molecular weight polyethylene (UHMWPE) was added as binder and reinforces the nepheline ceramics based geopolymer. The samples were sintered at 900 °C, 1000 °C, 1100 °C, and 1200 °C to elucidate the influence of sintering on the physical and microstructural properties. The results indicated that a maximum flexural strength of 92 MPa is attainable once the samples are used to be sintered at 1200 °C. It was also determined that the density, porosity, volumetric shrinkage, and water absorption of the samples also affected by the sintering due to the change of microstructure and crystallinity. The IR spectra reveal that the band at around 1400 cm−1 becomes weak, indicating that sodium carbonate decomposed and began to react with the silica and alumina released from gels to form nepheline phases. The sintering process influence in the development of the final microstructure thus improving the properties of the ceramic materials.

scholarly journals Pressureless sinterability study of ZrB2–SiC composites containing hexagonal BN and phenolic resin additives

2021 ◽  
Vol 1 (2) ◽  
pp. 99-104
Author(s):  
Iman FarahBakhsh ◽  
Riccarda Antiochia ◽  
Ho Won Jang
Keyword(s):  
Phenolic Resin ◽  
Vacuum Furnace ◽  
Sintering Process ◽  
Powder Mixtures ◽  
Cold Pressing ◽  
X Ray ◽  
Sic Ceramics ◽  
Sic Composites ◽  
By Products

This research is dedicated to the role of different amounts of hexagonal BN (hBN: 0, 1.5, 3, and 4.5 wt%) on the pressureless sinterability of ZrB2–25 vol% SiC ceramics. Phenolic resin (5 wt%) with a carbon yield of ~40 % was incorporated as a binder to the powder mixtures and after initial cold pressing, the final sintering process was performed at 1900 °C for 100 min in a vacuum furnace. The as-sintered specimens were characterized by X-ray diffractometry, field emission scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The results disclosed that the incorporation of 1.5 wt% hBN could increase the relative density to ~92%, while the sample with zero hBN content just reached ~81% of full densification. Appropriate hBN content not only facilitated the particle rearrangement during the cold pressing, but also removed the harmful oxide impurities during the final sintering. Nevertheless, the addition of higher amounts of hBN remarkably lessened the densification because of more delamination of the non-reacted hBN flakes and release and entrapment of more gaseous by-products induced by the reacted hBN phases.

Performance of Injection-Molded Plastic Helical Gears Finished by Hot Rolling

2011 ◽  
Author(s):  
Morimasa Nakamura ◽  
Atsushi Katayama ◽  
Ichiro Moriwaki
Keyword(s):  
Injection Molding ◽  
Hot Rolling ◽  
Load Capacity ◽  
Transmission Error ◽  
Tooth Profile ◽  
Test Rig ◽  
Helical Gears ◽  
Injection Molded ◽  
Injection Molded Plastic ◽  
Plastic Gears

A hot-roll finishing was proposed as a simple finishing method for plastic gears. In the hot-roll finishing, plastic work gears are finished by meshing with a heated copper die wheel. In the previous study, a hot-roll finishing rig for plastic gears was developed, and it was confirmed that tooth profiles of hobbed plastic gears are improved by the finishing. Thus, the hot-roll finishing could also be effective for injection-molded plastic gears. In the present paper, appropriate hot-roll finishing procedures for injection-molded polyoxymethylene (POM) helical gears were pursued. In the injection molding, an inadequate mold easily allows large slope deviations on a tooth profile and trace. The hot-roll finishing can reduce the slope deviations, but induces form deviations especially on the profile. Tests of injection-molded and hot-roll-finished plastic gears were performed on a self-produced gear roller test rig and a self-produced fatigue rig, and a transmission error and load capacity were estimated. Compared with injection-molded gears, hot-roll-finished plastic gears showed small transmission error, while a load capacity was at the almost same level. As a result, the hot-roll finishing is effective for improving a transmission error of injection-molded plastic gears.

scholarly journals Role of Carbon during Sintering Process in Fe-Ni Alloy Compacts Made by Injection Molding.

1996 ◽  
Vol 43 (5) ◽  
pp. 656-662 ◽  
Author(s):  
Hiroyuki Jinushi ◽  
Hideki Kyogoku ◽  
Kazumitsu Shinohara ◽  
Yoshihiro Takeyasu
Keyword(s):  
Injection Molding ◽  
Sintering Process ◽  
Ni Alloy

Sintering Behavior of the Powder Injection Molded Nanocrystalline Fe-50wt%Ni

2004 ◽  
Vol 449-452 ◽  
pp. 1141-1144 ◽  
Author(s):  
H.Y. Nam ◽  
S.K. Kwon ◽  
Young Soo Kang ◽  
Jai Sung Lee
Keyword(s):  
Particle Distribution ◽  
Powder Injection ◽  
Sintering Behavior ◽  
Impurity Effect ◽  
Microstructure Development ◽  
Sintering Process ◽  
Nano Powder ◽  
Homogeneous Particle ◽  
Injection Molded ◽  
Binder Material

Sintering process of powder injection molded (PIMed) Fe-50wt%Ni nanoalloyed powder was investigated in association with microstructure development and residual impurity effect. Compared to conventional powder metallurgical (PM) processed Fe-Ni nanoalloy powder, the PIM compact showed a homogeneous and uniform densification behavior. This is owing to more homogeneous particle distribution in the PIM resulting from preparation of feedstock which was fabricated by mixing of nano powder with thermoplastic binder. Residual impurities originating from the binder material did not have any apparent influences on sintering behavior. Conclusively, Fe-50wt%Ni nanoalloy powder is effectively applicable to the PIM parts.

Ionic Conductivity of Na2SO4–Al2O3 Composite Electrolytes: Mechanism and the Role of the Preparatory Parameters

2000 ◽  
Vol 153 (2) ◽  
pp. 287-293 ◽  
Author(s):  
Ashish Jain ◽  
Sandeep Saha ◽  
Prakash Gopalan ◽  
Ajit Kulkarni
Keyword(s):  
Ionic Conductivity ◽  
Composite Electrolytes ◽  
Al2o3 Composite
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