Abstract: <SPAN lang=EN-US style="FONT-SIZE: 10.5pt; FONT-FAMILY: " mso-bidi-language: ZH-CN; mso-fareast-language: EN-US; mso-ansi-language: 1.0pt; mso-font-kerning: mso-fareast-font-family: 12.0pt; mso-bidi-font-size: Roman?; New Times AR-SA; 宋体?>Silicon nitride powder was prepared by high-temperature self-propagating synthesis method,and which was ground to ultrafine level by stirring ball milling.Powder</SPAN><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-ascii-font-family: " AR-SA? mso-bidi-language: ZH-CN; mso-fareast-language: EN-US; mso-ansi-language: 1.0pt; mso-font-kerning: 12.0pt; mso-bidi-font-size: Roman?; New Times ?Times mso-bidi-font-family: mso-hansi-font-family:>′</SPAN><SPAN lang=EN-US style="FONT-SIZE: 10.5pt; FONT-FAMILY: " mso-bidi-language: ZH-CN; mso-fareast-language: EN-US; mso-ansi-language: 1.0pt; mso-font-kerning: mso-fareast-font-family: 12.0pt; mso-bidi-font-size: Roman?; New Times AR-SA; 宋体?>s particle size,morphology,and XRD pattern in different ball milling process conditions were tested and the influences of different process parameters of ball milling on particle size,morphology,and crystal lattice type were discussed.Finally,suitable stirring milling process parameters were confirmed,i.e.optimized process parameters were as follows:mass fraction ratio of powder to solvent was 1</SPAN><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-ascii-font-family: " AR-SA? mso-bidi-language: ZH-CN; mso-fareast-language: EN-US; mso-ansi-language: 1.0pt; mso-font-kerning: 12.0pt; mso-bidi-font-size: Roman?; New Times ?Times mso-bidi-font-family: mso-hansi-font-family:>∶</SPAN><SPAN lang=EN-US style="FONT-SIZE: 10.5pt; FONT-FAMILY: " mso-bidi-language: ZH-CN; mso-fareast-language: EN-US; mso-ansi-language: 1.0pt; mso-font-kerning: mso-fareast-font-family: 12.0pt; mso-bidi-font-size: Roman?; New Times AR-SA; 宋体?>1,mass fraction ratio of powder to </SPAN><SPAN lang=EN-US style="FONT-SIZE: 10.5pt; FONT-FAMILY: " mso-bidi-language: ZH-CN; mso-fareast-language: EN-US; mso-ansi-language: 1.0pt; mso-font-kerning: mso-fareast-font-family: 12.0pt; mso-bidi-font-size: Roman?; New Times AR-SA; 宋体?>grinding</SPAN><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-ascii-font-family: " AR-SA? mso-bidi-language: ZH-CN; mso-fareast-language: EN-US; mso-ansi-language: 1.0pt; mso-font-kerning: 12.0pt; mso-bidi-font-size: Roman?; New Times ?Times mso-bidi-font-family: mso-hansi-font-family:></SPAN><SPAN lang=EN-US style="FONT-SIZE: 10.5pt; FONT-FAMILY: " mso-bidi-language: ZH-CN; mso-fareast-language: EN-US; mso-ansi-language: 1.0pt; mso-font-kerning: mso-fareast-font-family: 12.0pt; mso-bidi-font-size: Roman?; New Times AR-SA; 宋体?>medium was 1</SPAN><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-ascii-font-family: " AR-SA? mso-bidi-language: ZH-CN; mso-fareast-language: EN-US; mso-ansi-language: 1.0pt; mso-font-kerning: 12.0pt; mso-bidi-font-size: Roman?; New Times ?Times mso-bidi-font-family: mso-hansi-font-family:>∶</SPAN><SPAN lang=EN-US style="FONT-SIZE: 10.5pt; FONT-FAMILY: " mso-bidi-language: ZH-CN; mso-fareast-language: EN-US; mso-ansi-language: 1.0pt; mso-font-kerning: mso-fareast-font-family: 12.0pt; mso-bidi-font-size: Roman?; New Times AR-SA; 宋体?>3,and the best grinding time was at 8</SPAN><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-ascii-font-family: " AR-SA? mso-bidi-language: ZH-CN; mso-fareast-language: EN-US; mso-ansi-language: 1.0pt; mso-font-kerning: 12.0pt; mso-bidi-font-size: Roman?; New Times ?Times mso-bidi-font-family: mso-hansi-font-family:>～</SPAN><SPAN lang=EN-US style="FONT-SIZE: 10.5pt; FONT-FAMILY: " mso-bidi-language: ZH-CN; mso-fareast-language: EN-US; mso-ansi-language: 1.0pt; mso-font-kerning: mso-fareast-font-family: 12.0pt; mso-bidi-font-size: Roman?; New Times AR-SA; 宋体?>10 h.Under those conditions the silicon nitride powder with the median diameter about 0.719 </SPAN><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-ascii-font-family: " AR-SA? mso-bidi-language: ZH-CN; mso-fareast-language: EN-US; mso-ansi-language: 1.0pt; mso-font-kerning: 12.0pt; mso-bidi-font-size: Roman?; New Times ?Times mso-bidi-font-family: mso-hansi-font-family:>μ</SPAN><SPAN lang=EN-US style="FONT-SIZE: 10.5pt; FONT-FAMILY: " mso-bidi-language: ZH-CN; mso-fareast-language: EN-US; mso-ansi-language: 1.0pt; mso-font-kerning: mso-fareast-font-family: 12.0pt; mso-bidi-font-size: Roman?; New Times AR-SA; 宋体?>m can be prepared by stirring ball milling method from the silicon nitride powder with the median diameter of about 5 </SPAN><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-ascii-font-family: " AR-SA? mso-bidi-language: ZH-CN; mso-fareast-language: EN-US; mso-ansi-language: 1.0pt; mso-font-kerning: 12.0pt; mso-bidi-font-size: Roman?; New Times ?Times mso-bidi-font-family: mso-hansi-font-family:>μ</SPAN><SPAN lang=EN-US style="FONT-SIZE: 10.5pt; FONT-FAMILY: " mso-bidi-language: ZH-CN; mso-fareast-language: EN-US; mso-ansi-language: 1.0pt; mso-font-kerning: mso-fareast-font-family: 12.0pt; mso-bidi-font-size: Roman?; New Times AR-SA; 宋体?>m. </SPAN>