Silicon nitride (Si{sub}3N{sub}4) is an important structural ceramic with various applications such as engine components, bearings and cutting tools. Si{sub}3N{sub}4 ceramics are generally machined using grinding, which induces surface and subsurface defects in the material. Such defects adversely affect the mechanical properties of Si{sub}3N{sub}4 due to its sensitivity to surface and subsurface flaws. In this paper, a carbon-dioxide (CO{sub}2) continuous wave laser has been used to anneal these defects and to improve the properties of Si{sub}3N{sub}4 after grinding. Various analytical techniques have been employed to evaluate the properties of the Si{sub}3N{sub}4 samples before and after the laser treatment. The results obtained indicate that both the surface integrity and the mechanical properties of Si{sub}3N{sub}4 samples are improved. Thus, high quality Si{sub}3N{sub}4 ceramic surfaces can be obtained by implementing this novel surface processing technique.
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