scholarly journals Optimization of Sintering Process of Alumina Ceramics Using Response Surface Methodology

2021 ◽  
Vol 13 (12) ◽  
pp. 6739
Author(s):  
Darko Landek ◽  
Lidija Ćurković ◽  
Ivana Gabelica ◽  
Mihone Kerolli Mustafa ◽  
Irena Žmak

In this work, alumina (Al2O3) ceramics were prepared using an environmentally friendly slip casting method. To this end, highly concentrated (70 wt.%) aqueous suspensions of alumina (Al2O3) were prepared with different amounts of the ammonium salt of a polycarboxylic acid, Dolapix CE 64, as an electrosteric dispersant. The stability of highly concentrated Al2O3 aqueous suspensions was monitored by viscosity measurements. Green bodies (ceramics before sintering) were obtained by pouring the stable Al2O3 aqueous suspensions into dry porous plaster molds. The obtained Al2O3 ceramic green bodies were sintered in the electric furnace. Analysis of the effect of three sintering parameters (sintering temperature, heating rate and holding time) on the density of alumina ceramics was performed using the response surface methodology (RSM), based on experimental data obtained according to Box–Behnken experimental design, using the software Design-Expert. From the statistical analysis, linear and nonlinear models with added first-order interaction were developed for prediction and optimization of density-dependent variables: sintering temperature, heating rate and holding time.

2002 ◽  
Vol 11 (2) ◽  
pp. 096369350201100
Author(s):  
E. S. Thian ◽  
N. H. Loh ◽  
K. A. Khor ◽  
S. B. Tor

Prior to the actual sintering process, a dilatometry study is performed to provide basic information and guidelines. This paper studies the effects of three sintering factors: sintering temperature, heating rate and holding time, on the densification rate of Ti-6Al-4V/HA composite parts. According to the in-situ test results, suitable values for the sintering factors can then be established.


2012 ◽  
Vol 581-582 ◽  
pp. 782-785
Author(s):  
Bin Meng ◽  
Jin Hui Peng

The mullite whiskers were synthesized from commercial raw materials by sintering in air. Three factors influencing the aspect ratio of whiskers, including sintering temperature, holding time and addition amount of V2O5, were analyzed based on single factor design and response surface methodology respectively. The optimum conditions for the synthesis of mullite whiskers with highest aspect ratio was obtained, i.e. sintering temperature was 1316.87°C, addition amount of V2O5 was 4.09wt.% and holding time was 1.96h. The experiment at the optimum condition was conducted and the real experimental value agrees to the predicted value based on response surface methodology.


2014 ◽  
Vol 541-542 ◽  
pp. 949-953
Author(s):  
Ying Yang ◽  
Wen Xuan Zheng

Biomass pyrolysis is a good high-value process of biomass conversion. Study on the pyrolysis products of crushed cotton stalks pyrolysis experiments in the self-made airtight equipment. The effects of three factors (pyrolysis temperature,pyrolysis heating rate and pyrolysis holding time) were investigated by using the mass of the solid products yield as the indexes .Box-Benhnken design ( BBD ) and response surface methodology ( RSM) were adopted to obtain the optimum parameters on the basis of results of single-factor experiments.The results show that: when pyrolysis temperature is 500°C.the heating rate is 9°C/min and holding time is 1h,solid products yield 33.4123%, liquid products yield 36.5699%, and gaseous products yield 30.0178%.


Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1741
Author(s):  
Xin Sun ◽  
Jialing Vivien Chua ◽  
Quynh Anh Le ◽  
Francisco Trujillo ◽  
Mi-Hwa Oh ◽  
...  

The response surface methodology (RSM) and central composite design (CCD) technique were used to optimize the three key process parameters (i.e., pressure, temperature and holding time) of the high-hydrostatic-pressure (HHP) processing either standalone or combined with moderate thermal processing to modulate molecular structures of β-lactoglobulin (β-Lg) and α-lactalbumin (α-La) with reduced human IgE-reactivity. The RSM model derived for HHP-induced molecular changes of β-Lg determined immunochemically showed that temperature (temp), pressure (p2) and the interaction between temperature and time (t) had statistically significant effects (p < 0.05). The optimal condition defined as minimum (β-Lg specific) IgG-binding derived from the model was 505 MPa at 56 °C with a holding time of 102 min (R2 of 0.81 and p-value of 0.01). The validation carried at the optimal condition and its surrounding region showed that the model to be underestimating the β-Lg structure modification. The molecular change of β-Lg was directly correlated with HHP-induced dimerization in this study, which followed a quadratic equation. The β-Lg dimers also resulted in the undetectable human IgE-binding.


2012 ◽  
Vol 581-582 ◽  
pp. 819-822 ◽  
Author(s):  
Bin Meng ◽  
Jin Hui Peng

The corundum-mullite was toughened by in-situ synthesized mullite whiskers and the process parameters influencing the fracture toughness of corundum-mullite, such as sintering temperature, addition amount of AlF3 and V2O5, were optimized by means of response surface method. Corundum-mullite with fracture toughness of 9.44 MPa.m-1/2 could be obtained under the optimized conditions, i.e. sintering temperature of 1400°C, 4.8 wt.% of AlF3 and 5.8 wt.% of V2O5. The results showed that it was feasible to prepare corundum-mullite toughened by in-situ synthesized mullite whiskers by the optimized parameters. In addition, an accurate model based on response surface method was proposed to predict the experimental results.


Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1086 ◽  
Author(s):  
Dilpreet Singh ◽  
Abhishek Rana ◽  
Pawan Sharma ◽  
Pulak Mohan Pandey ◽  
Dinesh Kalyanasundaram

Pressureless sintering is a powder metallurgical process wherein the powder particles are sintered without the aid of any compressive force. Though this additive manufacturing process is economical, the strength of the component is undermined due to the presence of pores; the elimination of which is a challenge. In this work, the optimal process parameters for the pressureless microwave sintering of a grade 5 titanium alloy that yields higher tensile strength and minimum sizes of pores were obtained. The three process parameters (sintering temperature, heating rate, and holding time) were experimented at five different levels using the design of experiments (DOE). Post sintering, the tensile strength was assessed as per ASTM standard B925-15, while the pore size was evaluated, non-destructively, using micro-computed tomography (μ-CT). The optimal process parameters that yielded minimum size pores were: sintering temperature—1293 °C, heating rate— 6.65 C/minute; and holding time—72 min.


1987 ◽  
Vol 01 (02) ◽  
pp. 267-272 ◽  
Author(s):  
Liquan Chen ◽  
Zhili Xiao ◽  
Yuzhen Huang ◽  
Zhenhong Mai ◽  
Xi Chu ◽  
...  

Some factors which might effect on Tco during the sintering procedure have been studied. These factors include the sintering time, sintering temperature, heating rate, cooling rate, oxygen pressure, annealing in different atmosphere and multiple sintering as well. The attention has also paid to the influence of Al3+ which might be introduced by using Al2O3 crucible.


2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Xuan Wei ◽  
Dengfei Jie

The production and nature of the biocrude obtained from Spirulina sp. by hydrothermal liquefaction (HTL) technology is focused in this investigation. Our aim is to evaluate the interaction of different factors on the bio-oil production through HTL using microalgae that contains relatively low lipid content and high protein. Optimization of three key parameters—concentration (mass of algae per mass of solvent), reaction temperature, and holding time—was carried out by response surface methodology (RSM). In this work, we used central composite design to conduct the experiment process. Graphical response surface and contour plots were used to locate the optimum point. The final results showed that the optimum concentration, temperature, and holding time were 10.5%, 357°C, and 37 min, respectively. Under the optimum conditions established, yield of the biocrude (41.6 ± 2.2%) was experimentally obtained using the fresh microalgae. This study showed the potential of bio-oil production of Spirulina sp. by HTL technology, but it still needs more improvement of the biocrude for utilization.


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