Effect of Sintering Process Parameters on the Properties of 3Y-PSZ Ceramics

2013 ◽  
Vol 749 ◽  
pp. 44-48 ◽  
Author(s):  
Husieh Liang Chu ◽  
Cheng Li Wang ◽  
Huey Er Lee ◽  
Yu You Sie ◽  
Rong Sheng Chen ◽  
...  
Keyword(s):  
Relative Density ◽  
Process Parameters ◽  
Significant Influence ◽  
Vickers Hardness ◽  
Sintered Pellet ◽  
Densification Behavior ◽  
Sintering Process ◽  
Sintered Temperature

The effect of sintering process parameters on the properties of 3 mol% yttria partially stability zirconia (3Y-PSZ) ceramics has been investigated. The relative density of the sintered pellet rapidly increases from 70.5 to 93.6 % with rose temperature from 1473 to 1573 K. In addition, the relative density only slightly increases from 94.9 to 96.6 %, when rose sintered temperature from 1573 to 1773 K. This result shows that no significant influence on the densification behavior when sintering at 1573 to 1773 K for 2 h. The Vickers hardness and toughness also increase with the sintered temperature.

Influence of Selective Laser Melting Process Parameters on Densification Behavior, Surface Quality and Hardness of 18Ni300 Steel

2020 ◽  
Vol 861 ◽  
pp. 77-82
Author(s):  
Gan Li ◽  
Cheng Guo ◽  
Wen Feng Guo ◽  
Hong Xing Lu ◽  
Lin Ju Wen ◽  
...  
Keyword(s):  
Energy Density ◽  
Relative Density ◽  
Maraging Steel ◽  
Surface Quality ◽  
Selective Laser Melting ◽  
Process Parameters ◽  
Laser Power ◽  
Densification Behavior ◽  
Laser Melting ◽  
Scan Speed

This study investigated the effect of laser power (P), scan speed (v) and hatch space (h) on densification behavior, surface quality and hardness of 18Ni300 maraging steel fabricated by selective laser melting (SLM). The results indicated that the relative density of the SLMed samples has a shape increase from 73% to 97% with the laser energy density increasing from 0.5 to 2.2 J/mm2. The relative density ≥ 99% was achieved at the energy density in the range of 2.2~5.9 J/mm2. The optimum process parameters were found to be laser power of 150~200 W, scan speed of 600mm/s and hatch space of 0.105mm. In addition, it was found that the hardness increased initially with the increasing relative density up to relative density of 90% and then little relationship, but finally increase again significantly. This work provides reference for determining process parameters for SLMed maraging steel and the development of 3D printing of die steels.

Manufacture of Al/SiC Composites by Pressure Infiltration Process

2005 ◽  
Vol 475-479 ◽  
pp. 913-916
Author(s):  
Fa Zhang Yin ◽  
Cheng Chang Jia ◽  
Xuezhen Mei ◽  
Bin Ye ◽  
Yanlei Ping ◽  
...  
Keyword(s):  
Relative Density ◽  
Process Parameters ◽  
Room Temperature ◽  
Sintering Process ◽  
Homogeneous Microstructure ◽  
Infiltration Process ◽  
Pressure Infiltration ◽  
Upper Limit ◽  
Thermal Debinding ◽  
Sic Composites

The SiCp performing sample was made first then Al/SiCp (65%) was manufactured. Appropriate component and proportion of binder and process parameters were selected to control the porosity. Debinding has succeeded by extractive and thermal debinding processes. SiCp preforming samples with good appearance, enough strength, and right porosity were obtained by pre-sintering process at 1100°C. Composites with high density and homogeneous microstructure were manufactured by pressure infiltration under 1050°C and 15MPa. The distribution of aluminium and silicon elements was homogeneous. The primary components of materials are aluminium, β-SiC and α-SiC. The thermal expand coefficient of composites is 8.0×10-6/°C at room temperature, which increases with temperature and reaches to 11.0×10-6/°C at 300°C. The density is 2.92g/cm3, and relative density is more than 97 %. The strength is about 500MPa, approaching to the upper limit of the theoretical value.

The Investigation of Ultrahigh Pressuer Sintering of Cubic Boron Nitride with the Binding Agent of Si3N4

2010 ◽  
Vol 150-151 ◽  
pp. 1191-1194
Author(s):  
Shao Jie Lin ◽  
Yi Wu ◽  
Zheng Guang Zou ◽  
Yu Fang Shen
Keyword(s):  
Phase Transformation ◽  
Boron Nitride ◽  
Flexural Strength ◽  
Relative Density ◽  
Vickers Hardness ◽  
Cubic Boron Nitride ◽  
Sintering Process ◽  
Binding Agent ◽  
Sintered Compact ◽  
Polycrystalline Cubic Boron Nitride

Selecting Si3N4 as binding agent and Al2O3–Al–Y2O3 as sintering additives, the sintered compact of polycrystalline cubic boron nitride (PcBN) was studied . By modifying the ratio of each component and the parameters of the sintering process, the compact sintered at 4.5 GPa and 1650 °C showed good mechanical properties.The phase constitution, microstructure of the sintered compact were characterized by XRD and SEM respectively. The degree of phase transformation of Si3N4 , the chemical reaction during the sintering process, and the sintering mechanism of the additives were discussed . The best relative density is more than 97 % , the flexural strength is more than 650 MPa, the Vickers hardness Hv is more than 8.7 GPa.

Addition of Nano-ZrO2 Effects on Microstructures and Properties of WC-8Co Hard Alloys

2012 ◽  
Vol 496 ◽  
pp. 302-305 ◽  
Author(s):  
Lan Sun
Keyword(s):  
Mechanical Properties ◽  
Phase Transition ◽  
Fracture Toughness ◽  
Relative Density ◽  
Hard Alloys ◽  
Densification Behavior ◽  
Sintering Process ◽  
Toughening Mechanism ◽  
Hard Metals ◽  
Conventional Sintering

This paper carries out the research on using the toughening mechanism of phase transition of ZrO2 to inhibit the WC grain and improve the toughness of the hard alloys. WC–ZrO2–8wt%Co hard metals was mixed with 0-2 wt% nano-ZrO2 and prepared by conventional sintering (CS) for 2 h at 1440oC to see whether the addition of ZrO2 could improve densification behavior, the microstructure and mechanical properties of the samples. Experimental results showed that the use of ZrO2 nanoparticles could decrease the relative density because of the worse wetting effects; it could also inhibit the growth of the grains of WC-Co hardmetal to enhance the hardness of the alloy. The fracture toughness of sample has an increasing tendency as a whole because of the phase transition during the sintering process.

scholarly journals On the Relevance of Volumetric Energy Density in the Investigation of Inconel 718 Laser Powder Bed Fusion

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 538 ◽  
Author(s):  
Fabrizia Caiazzo ◽  
Vittorio Alfieri ◽  
Giuseppe Casalino
Keyword(s):  
Surface Roughness ◽  
Energy Density ◽  
Process Parameters ◽  
Vickers Hardness ◽  
Powder Bed Fusion ◽  
Processing Conditions ◽  
Laser Powder Bed Fusion ◽  
Powder Bed ◽  
Fractional Density ◽  
Experimental Variation

Laser powder bed fusion (LPBF) can fabricate products with tailored mechanical and surface properties. In fact, surface texture, roughness, pore size, the resulting fractional density, and microhardness highly depend on the processing conditions, which are very difficult to deal with. Therefore, this paper aims at investigating the relevance of the volumetric energy density (VED) that is a concise index of some governing factors with a potential operational use. This paper proves the fact that the observed experimental variation in the surface roughness, number and size of pores, the fractional density, and Vickers hardness can be explained in terms of VED that can help the investigator in dealing with several process parameters at once.

scholarly journals Pressureless Sintering of YIG Ceramics from Coprecipitated Nanopowders

2021 ◽  
Vol 7 (5) ◽  
pp. 56
Author(s):  
Yimin Yang ◽  
Xiaoying Li ◽  
Ziyu Liu ◽  
Dianjun Hu ◽  
Xin Liu ◽  
...  
Keyword(s):  
High Temperature ◽  
Calcination Temperature ◽  
Sintering Temperature ◽  
Raw Materials ◽  
Secondary Phase ◽  
Coprecipitation Method ◽  
Pressureless Sintering ◽  
Densification Behavior ◽  
Sintering Process

Nanoparticles prepared by the coprecipitation method were used as raw materials to fabricate Y3Fe5O12 (YIG) ceramics by air pressureless sintering. The synthesized YIG precursor was calcinated at 900–1100 °C for 4 h in air. The influences of the calcination temperature on the phase and morphology of the nanopowders were investigated in detail. The powders calcined at 1000–1100 °C retained the pure YIG phase. YIG ceramics were fabricated by sintering at 1200–1400 °C for 10 h, and its densification behavior was studied. YIG ceramics prepared by air sintering at 1250 °C from powders calcinated at 1000 °C have the highest in-line transmittance in the range of 1000-3000 nm. When the sintering temperature exceeds 1300 °C, the secondary phase appears in the YIG ceramics, which may be due to the loss of oxygen during the high-temperature sintering process, resulting in the conversion of Fe3+ into Fe2+.

scholarly journals Improvement of mechanical properties of HfB2-based composites by incorporating in situ SiC reinforcement through pressureless sintering

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
S. Ghadami ◽  
E. Taheri-Nassaj ◽  
H. R. Baharvandi ◽  
F. Ghadami
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Relative Density ◽  
Pressureless Sintering ◽  
Sintering Process ◽  
Vacuum Atmosphere ◽  
Sic Reinforcement ◽  
Microstructural Studies ◽  
Composite Samples

AbstractHfB2, Si, and activated carbon powders were selected to fabricate 0–30 vol% SiC reinforced HfB2-based composite. Pressureless sintering process was performed at 2050 °C for 4 h under a vacuum atmosphere. Microstructural studies revealed that in situ SiC reinforcement was formed and distributed in the composite according to the following reaction: Si + C = SiC. A maximum relative density of 98% was measured for the 20 vol% SiC containing HfB2 composite. Mechanical investigations showed that the hardness and the fracture toughness of these composites were increased and reached up to 21.2 GPa for HfB2-30 vol% SiC and 4.9 MPa.m1/2 for HfB2-20 vol% SiC, respectively. Results showed that alpha-SiC reinforcements were created jagged, irregular, and elongated in shape which were in situ formed between HfB2 grains and filled the porosities. Formation of alpha-SiC contributed to improving the relative density and mechanical properties of the composite samples. By increasing SiC content, an enhanced trend of thermal conductivity was observed as well as a reduced trend for electrical conductivity.

scholarly journals Effect of Process Parameters and High-Temperature Preheating on Residual Stress and Relative Density of Ti6Al4V Processed by Selective Laser Melting

Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 930 ◽  
Author(s):  
Martin Malý ◽  
Christian Höller ◽  
Mateusz Skalon ◽  
Benjamin Meier ◽  
Daniel Koutný ◽  
...  
Keyword(s):  
Residual Stress ◽  
High Temperature ◽  
Residual Stresses ◽  
Relative Density ◽  
Selective Laser Melting ◽  
Process Parameters ◽  
Stress Reduction ◽  
Laser Melting ◽  
Preheating Temperature ◽  
Laser Velocity

The aim of this study is to observe the effect of process parameters on residual stresses and relative density of Ti6Al4V samples produced by Selective Laser Melting. The investigated parameters were hatch laser power, hatch laser velocity, border laser velocity, high-temperature preheating and time delay. Residual stresses were evaluated by the bridge curvature method and relative density by the optical method. The effect of the observed process parameters was estimated by the design of experiment and surface response methods. It was found that for an effective residual stress reduction, the high preheating temperature was the most significant parameter. High preheating temperature also increased the relative density but caused changes in the chemical composition of Ti6Al4V unmelted powder. Chemical analysis proved that after one build job with high preheating temperature, oxygen and hydrogen content exceeded the ASTM B348 limits for Grade 5 titanium.

scholarly journals Analysis of Densification Behavior during Powder Equal Channel Angular Pressing using Critical Relative Density Model

2008 ◽  
Vol 15 (5) ◽  
pp. 365-370 ◽  
Author(s):  
Cheon-Hee Bok ◽  
Ji-Hoon Yoo ◽  
Seung-Chae Yoon ◽  
Taek-Soo Kim ◽  
Byong-Sun Chun ◽  
...  
Keyword(s):  
Relative Density ◽  
Equal Channel Angular Pressing ◽  
Density Model ◽  
Densification Behavior ◽  
Angular Pressing

Effects of Sintering Process on the Properties of Ti3SiC2/Cu Composite

2012 ◽  
Vol 512-515 ◽  
pp. 377-381 ◽  
Author(s):  
Jin Rong Lu ◽  
Yang Zhou ◽  
Yong Zheng ◽  
Shi Bo Li ◽  
Zhen Ying Huang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Vickers Hardness ◽  
Hot Pressing ◽  
Sintering Temperature ◽  
Sintering Process ◽  
Vacuum Sintering ◽  
New Type ◽  
Sintering Conditions ◽  
The Relationship ◽  
Better Than

In this paper, a new type of Ti3SiC2/Cu composites with the volume fractions of 30% Ti3SiC2 particle was prepared by hot pressing and vacuum sintering respectively. The effects of sintering temperature and holding time on the density, resistance and Vickers hardness of Cu-30vol%Ti3SiC2 composite were investigated. The results show that the mechanical properties of the composites prepared by hot pressing are better than that prepared by vacuum sintering. The relative densities of Cu-30vol% Ti3SiC2 composites are rather high in suitable sintering conditions. It achieved 100% for the composites prepared by hot pressing at 930°C for 2h, and 98.4% for the composites prepared by vacuum sintering at 1250°C for 1h. At the same time, the maximum Vickers hardness reached 1735MPa at 900°C by hot pressing. The resistance and Vickers hardness of the composites decreased with an increase in sintering temperature, whereas the density increased. Scanning electron microscope (SEM) and energy-dispersive spectroscopy (EDS) were used to observe the microstructure of the composites. The relationship between microstructure and mechanical properties was discussed.

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