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Study on Crack Repair Performance of Si3N4/TiC/ZrSi2 Ceramic Tool Materials.
- Source :
- China Mechanical Engineering; 10/10/2022, Vol. 33 Issue 19, p2288-2297, 10p
- Publication Year :
- 2022
-
Abstract
- To solve the problems that ceramic tools were sensitive to cracks, ZrSi<subscript>2</subscript> crack repairing agent was added into Si<subscript>3</subscript>N<subscript>4</subscript>/TiC ceramic tool material matrix, which made ceramic tools have crack repairing ability. When ZrS<subscript>i</subscript>2 content was as 10% (volumn fraction), Si<subscript>3</subscript>N<subscript>4</subscript>TiC/ZrSi<subscript>2</subscript> ceramic tool materials had better comprehensive properties, with flexural strength of 815 MPa, fracture toughness of 8.06 MPa ⋅ m<superscript>1/2</superscript>, Vickers hardness of 15.91 GPa and relative density of 99.72%). Cracks were introduced into the surface of ceramic tool materials by Vickers hardness tester, and the optimal repair parameters and repair mechanism of cracks in Si3N,/TiC-based ceramic materials with ZrSi<subscript>2</subscript> as repair agent, were studied. The research shows that the flexural strength of Si<subscript>3</subscript>N<subscript>4</subscript>TiC/ZrSi<subscript>2</subscript> prefabricated crack specimen with 10%) ZrSi<subscript>2</subscript> added may be restored to 92.02%) of that of smooth specimen after heat treatment at 800 °C for 60 min in air atmosphere, and the crack with the surface length of 300 ~ 350 µm is completely repaired, and an oxide layer mainly composed of ZrO<subscript>2</subscript> and SiO<subscript>2</subscript> is formed on the surface of the specimen. The mechanism of crack repair of ceramic cutting tool materials is analyzed as follows-, in the air heat treatment processes, ZrSi<subscript>2</subscript>, a healing agent at the crack and the surface of the material, preferentially reacts with oxygen to generate ZrO<subscript>2</subscript> and SiO<subscript>2</subscript>, which heal the crack on the surface of the material and restore the strength of the crack sample. At the same time, during cutting, ZrO<subscript>2</subscript> and SiO<subscript>2</subscript>, oxidation products of ZrSi<subscript>2</subscript> at the cracks and material surfaces, may repair the crack in time and improve the wear resistance of the tool. [ABSTRACT FROM AUTHOR]
Details
- Language :
- Chinese
- ISSN :
- 1004132X
- Volume :
- 33
- Issue :
- 19
- Database :
- Complementary Index
- Journal :
- China Mechanical Engineering
- Publication Type :
- Academic Journal
- Accession number :
- 160277316
- Full Text :
- https://doi.org/10.3969/j.issn.1004-132X.2022.19.002