Analysis of the growth mechanism of TiC crystal and the mechanical properties of the laser alloyed layer on the surface of pure titanium

TIAN Yong-sheng; CHEN Chuan-zhong; WANG De-yun; XU Ying; LEI Ting-quan

The laser-alloyed layer is fabricated on the surface of puretitanium with graphite powder.The microstructures and phase constituents of the alloyed layers are investigated by means of SEM,EPMA,XRD and HRTEM.The results show that a great deal of dendritic TiC crystals are formed in the alloyed layer.The growth mechanism of dendritic TiC crystals is theoretically analyzed,at first they continuously grow into dentritic TiC embryo crystals and then each of them acts as many nucleuses on which the lateral growths begin.So the final morphologies of dendritic TiC crystals look as if they were composed of crystallitic grains in a linear arrangement.The test results show that the hardness of the alloyed layers is much higher than that of the matrix and the wear coe fficient of alloyed layers is significantly lower than that of the substrate.Changing laser processing parameters can greatly affect the microstructures and mechanical properties of the alloyed layers,ideal alloyed surface can be achieved only if optimum parameters selected.

Corresponding author: CHEN Chuan-zhong, cczchen@sdu.edu.cn;

1. School of Materials Science and Engineering, Shandong University, ji'nan 250061, China;

2. School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China

Received Date: 2004-04-29

Accepted Date: 2004-06-15

Available Online: 2005-03-25

Abstract: The laser-alloyed layer is fabricated on the surface of puretitanium with graphite powder.The microstructures and phase constituents of the alloyed layers are investigated by means of SEM,EPMA,XRD and HRTEM.The results show that a great deal of dendritic TiC crystals are formed in the alloyed layer.The growth mechanism of dendritic TiC crystals is theoretically analyzed,at first they continuously grow into dentritic TiC embryo crystals and then each of them acts as many nucleuses on which the lateral growths begin.So the final morphologies of dendritic TiC crystals look as if they were composed of crystallitic grains in a linear arrangement.The test results show that the hardness of the alloyed layers is much higher than that of the matrix and the wear coe fficient of alloyed layers is significantly lower than that of the substrate.Changing laser processing parameters can greatly affect the microstructures and mechanical properties of the alloyed layers,ideal alloyed surface can be achieved only if optimum parameters selected.

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Reference (12)

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Analysis of the growth mechanism of TiC crystal and the mechanical properties of the laser alloyed layer on the surface of pure titanium

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References

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通讯作者: 陈斌, bchen63@163.com

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