Effect of sintering aids on mechanical properties and microstructure of alumina ceramic via stereolithography

Qian, Chuchu; Hu, Kehui; Shen, Zhongyao; Wang, Qing; Li, Peijie; Lu, Zongqing

doi:10.1016/j.ceramint.2023.02.118

Cited by 16 publications

(4 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This reduction in crystallite size can be attributed to the presence of CaO and MgO, which react with Al 2 O 3 to form CaO(Al 2 O 3 ) 6 and MgAl 2 O 4 . These phases inhibit the diffusion of Al 2 O 3 grains, preventing excessive growth at high temperatures and thus achieving a refinement of the grains [ 26 , 27 , 28 , 29 ]. X-ray diffraction analysis shows that at some point in the sintering process, CaO produced from SFs reacts with Al 2 O 3 to generate CaO(Al 2 O 3 ) 6, which can inhibit the formation of a glassy phase, preventing abnormal grain growth [ 22 ], thus improving the flexural strength of Al 2 O 3 parts [ 30 ]; meanwhile, 316L SS generates NiO and NiCr 2 O 4 .…”

Section: Resultsmentioning

confidence: 99%

Vat Photopolymerization of Sepiolite Fiber and 316L Stainless Steel-Reinforced Alumina with Functionally Graded Structures

Liu,

Wu,

Guo

et al. 2024

Materials

View full text Add to dashboard Cite

Alumina (Al2O3) ceramics are widely used in electronics, machinery, healthcare, and other fields due to their excellent hardness and high temperature stability. However, their high brittleness limits further applications, such as artificial ceramic implants and highly flexible protective gear. To address the limitations of single-phase toughening in Al2O3 ceramics, some researchers have introduced a second phase to enhance these ceramics. However, introducing a single phase still limits the range of performance improvement. Therefore, this study explores the printing of Al2O3 ceramics by adding two different phases. Additionally, a new gradient printing technique is proposed to overcome the limitations of single material homogeneity, such as uniform performance and the presence of large residual stresses. Unlike traditional vat photopolymerization printing technology, this study stands out by generating green bodies with varying second-phase particle ratios across different layers. This study investigated the effects of different contents of sepiolite fiber (SF) and 316L stainless steel (SS) on various aspects of microstructure, phase composition, physical properties, and mechanical properties of gradient-printed Al2O3. The experimental results demonstrate that compared to Al2O3 parts without added SF and 316L SS, the inclusion of these materials can significantly reduce porosity and water absorption, resulting in a denser structure. In addition, the substantial improvements, with an increase of 394.4% in flexural strength and an increase of 316.7% in toughness, of the Al2O3 components enhanced by incorporating SF and 316L SS have been obtained.

show abstract

Section: Resultsmentioning

confidence: 99%

Vat Photopolymerization of Sepiolite Fiber and 316L Stainless Steel-Reinforced Alumina with Functionally Graded Structures

Liu,

Wu,

Guo

et al. 2024

Materials

View full text Add to dashboard Cite

show abstract

“…20 However, by this method, a rapid decrease in flexural strength easily occurs when the porosity is increased to more than 30%, with a maximum value of less than 60 MPa. [21][22][23][24][25][26][27][28][29] With the increasing complexity of ceramic core shapes, the requirements for core strength are increasing correspondingly. Therefore, the development of high-strength and high-porosity Al 2 O 3 ceramic cores has become a core problem that needs to be solved urgently.…”

Section: Introductionmentioning

confidence: 99%

“…Most of the current studies to enhance the performance of Al 2 O 3 ceramic cores focus on changing the degreasing and sintering process 20 . However, by this method, a rapid decrease in flexural strength easily occurs when the porosity is increased to more than 30%, with a maximum value of less than 60 MPa 21–29 . With the increasing complexity of ceramic core shapes, the requirements for core strength are increasing correspondingly.…”

Section: Introductionmentioning

confidence: 99%

Vat photopolymerization 3D printing of Al₂O₃ ceramic cores with strip‐shaped pores by using polyamide 6 fiber template

Zhai,

Chen,

et al. 2024

J Am Ceram Soc.

View full text Add to dashboard Cite

The complex ceramic core used for hollow turbine blades requires high porosity and flexural strength. This work combined vat photopolymerization 3D printing with sacrificial template method to prepare Al2O3 ceramic cores with strip‐shaped pores using polyamide 6 (PA6) fibers as templates. When the porosity was greater than 30%, the maximum flexural strength reached up to 110.48 MPa. The sacrificial templating method improved the porosity of Al2O3 ceramic cores, forming an internal porous structure that combined strip‐shaped large pores with irregularly shaped small pores. The influences of PA6 fiber content and diameter on the shrinkage, porosity, microstructure, and comprehensive properties of alumina ceramic cores were studied, revealing the mechanism of the coexistence of high porosity and high strength.

show abstract

“…In the past few years, some fundamental studies have discovered that the modification of a single component of common ceramic oxides, i.e., the introduction of additives, can theoretically suppress the growth of grains and induce grain refinement, thus enhancing the strength and toughness of ceramics to a certain extent and ultimately achieving a reduction in sintering temperature [ 15 , 16 , 17 , 18 ]. For instance, Wang et al [ 19 ] investigated the microstructural evolution of Al 2 O 3 with different Nd 2 O 3 additions, showing that the addition of neodymium inhibits the densification of Al 2 O 3 through grain boundary segregation.…”

Section: Introductionmentioning

confidence: 99%

Reducing Water Absorption and Improving Flexural Strength of Aluminosilicate Ceramics by MnO2 Doping

Yang,

Lu,

et al. 2024

Materials

View full text Add to dashboard Cite

As key performance indicators, the water absorption and mechanical strength of ceramics are highly associated with sintering temperature. Lower sintering temperatures, although favorable for energy saving in ceramics production, normally render the densification degree and water absorption of as-prepared ceramics to largely decline and increase, respectively. In the present work, 0.5 wt.% MnO2, serving as an additive, was mixed with aluminosilicate ceramics using mechanical stirring at room temperature, achieving a flexural strength of 58.36 MPa and water absorption of 0.05% and lowering the sintering temperature by 50 °C concurrently. On the basis of the results of TG-DSC, XRD, MIP, and XPS, etc., we speculate that the MnO2 additive promoted the elimination of water vapor in the ceramic bodies, effectively suppressing the generation of pores in the sintering process and facilitating the densification of ceramics at a lower temperature. This is probably because the MnO2 transformed into a liquid phase in the sintering process flows into the gap between grains, which removed the gas inside pores and filled the pores, suppressing the generation of pores and the abnormal growth of grains. This study demonstrated a facile and economical method to reduce the porosity and enhance the densification degree in the practical production of aluminosilicate ceramics.

show abstract

Effect of sintering aids on mechanical properties and microstructure of alumina ceramic via stereolithography

Cited by 16 publications

References 49 publications

Vat Photopolymerization of Sepiolite Fiber and 316L Stainless Steel-Reinforced Alumina with Functionally Graded Structures

Vat Photopolymerization of Sepiolite Fiber and 316L Stainless Steel-Reinforced Alumina with Functionally Graded Structures

Vat photopolymerization 3D printing of Al₂O₃ ceramic cores with strip‐shaped pores by using polyamide 6 fiber template

Reducing Water Absorption and Improving Flexural Strength of Aluminosilicate Ceramics by MnO2 Doping

Contact Info

Product

Resources

About

Effect of sintering aids on mechanical properties and microstructure of alumina ceramic via stereolithography

Cited by 16 publications

References 49 publications

Vat Photopolymerization of Sepiolite Fiber and 316L Stainless Steel-Reinforced Alumina with Functionally Graded Structures

Vat Photopolymerization of Sepiolite Fiber and 316L Stainless Steel-Reinforced Alumina with Functionally Graded Structures

Vat photopolymerization 3D printing of Al2O3 ceramic cores with strip‐shaped pores by using polyamide 6 fiber template

Reducing Water Absorption and Improving Flexural Strength of Aluminosilicate Ceramics by MnO2 Doping

Contact Info

Product

Resources

About

Vat photopolymerization 3D printing of Al₂O₃ ceramic cores with strip‐shaped pores by using polyamide 6 fiber template