高分子材料SLS中次级烧结实验  

Secondary sintering of selective laser sintering polymeric materials

作　　者：闫春泽[1] 史玉升[1] 杨劲松[1] 黄树槐[1] 

机构地区：[1]华中科技大学材料成形与模具技术国家重点实验室,湖北武汉430074

出　　处：《华中科技大学学报（自然科学版）》2008年第5期86-89,共4页Journal of Huazhong University of Science and Technology(Natural Science Edition)

基　　金：国家科技型中小企业创新基金资助项目(05C262142011059);聚合物成型加工工程教育部重点实验室开放课题资助项目(20061006)

摘　　要：针对选择性激光烧结(SLS)成形中次级烧结严重影响成形件精度的问题,分析了次级烧结的形成原因,通过聚苯乙烯、尼龙12及玻璃微珠填充尼龙12三种典型的烧结材料,对SLS成形过程中影响次级烧结的因素进行了实验研究.结果表明"次级烧结是由于已烧结部分向其周围的松散粉末传热,使其达到结块温度而引起的,主要表现在烧结件轮廓模糊和尺寸变大.提高预热温度和激光能量密度都会增大次级烧结,而通过添加高熔点的无机填料可以降低次级烧结,半结晶性高分子材料由于存在熔融潜热,次级烧结明显低于非结晶性高分子材料.Secondary sintering widely exists in the processing of selective laser sintering （SLS）, which seriously affects the dimensional accuracy of sintered parts. The cause of secondary sintering was analyzed. By studying the sintering characteristics of three typical SLS materials, polystyrene powder, nylon 12 and glass beam reinforced nylon12 power, the factors affecting secondary sintering were investigated. The results show. because of the temperature gradient between the sintered part and loose powder around it, heat transfer causes the temperature of the loose powder rising to its caking temperature, then secondary sintering happens; the extent of secondary sintering increases with increasing part bed temperature and laser energy density; the extent of secondary sintering of inorganic filler reinforced polymers powder is smaller than that of neat polymers powder; in SLS process, secondary sintering of amorphous polymers is easier to happen than that of semi-crystalline polymers. It gave important guidance to control secondary sintering and improve the dimensional accuracy of sintered parts.

关 键 词：快速成形 选择性激光烧结 高分子材料 次级烧结 实验研究 

分 类 号：TB324[一般工业技术—材料科学与工程]