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| Effects of different binder and sintering temperature on mechanical properties and microstructure of alumina ceramics |
| CAO Yu，HU Jilin，CHEN Zhanjun，LIU Zhehao，CHEN Du，PENG Yangxi |
| （Hunan Provincial Key Laboratory of Fine Ceramics and Powder Materials, School of Materials and Environmen‐
tal Engineering, Hunan University of Humanities, Science and Technology, Loudi 417000, China） |
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Abstract Alumina ceramics were prepared by pressureless sintering at 1 500~1 600 ℃ using ultrafine Al2O3
powder as the main raw material, adding a certain amount of yttrium oxide, lanthanum oxide, magnesium oxide
and other sintering aids, and adding No.1(5% polyvinyl alcohol A), No.2(5% gum arabic ) and No.3(2% polyeth‐
ylene glycol and 6% polyvinyl alcohol B) binders respectively. The effects of different kinds of binders and sin‐
tering temperature on the related properties and microstructure of Al2O3 ceramics were comparatively studied by
analyzing the volume shrinkage, bulk density, flexural strength, Vickers hardness, phase composition and micro‐
structure of Al
2O3 ceramic samples. The results show that the hardness and strength of ceramic samples with No.1
and No.3 binders increase with the increase of sintering temperature, and reach the maximum value at 1 600 ℃.
However, the hardness of ceramic samples with No.2 binder increases first and then decreases with the increase of sintering temperature, and reaches the maximum value (892.5HV) at 1 550 ℃. Compared with No.2 and No.3
binders, the Al2O3 ceramic samples prepared by adding No.1 binder at 1 600 ℃ have the best comprehensive
properties, and their flexural strength and Vickers hardness reach 238.49 MPa and 991.7HV, respectively. The
Al
2O3 ceramic samples prepared under these conditions have a block-shaped broken grain structure, and the
traces left by the grains pulled out when the samples are fractured can be seen. The interface between the grains
is very closely bonded, giving the Al2O3 ceramics excellent comprehensive properties.
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Received: 24 August 2022
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Corresponding Authors:
胡继林（1978—），男，博士，教授，主要研究方向无机非金属材料。
陈占军（1982—），男，博士，副教授，主要研究方向为无机非金属材料。
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2023, Vol. 33 
