摘要
粉床的预热是激光选区烧结(SLS)加工过程中一个非常重要的环节,预热均匀性对零件的成形效率和精度有着重要影响。针对大型SLS装备(2 m×2 m),由于粉床区域面积较大,粉床全场温度均匀性难以达到要求等问题,提出了分区域预热温度控制方法,建立基于辐射能系数的数值分析模型,搭建了实验平台,以尼龙12作为试验材料,开展预热试验研究,验证了数值模型的准确性,获得了大型SLS装备的最佳预热策略。试验结果表明,以尺寸为2 m×2 m尼龙12粉床为控制对象,使全场温度差控制在5℃,满足了工艺指标要求,为实现大型SLS装备研制、成形精度控制等关键问题提供技术支撑。
Preheating of the powder bed is a very important step in the process of selective laser sintering(SLS), the uniformity of preheating temperature has an important influence on the efficiency and precision of parts. For the large SLS equipment(2 m×2 m), it is difficult to meet the requirements of the temperature uniformity of the powder bed due to the large area of the powder bed. The new preheating method is proposed based on subarea control. The numerical analysis model is established based on coefficient of radiant energy, experimental platform is built, and nylon 12 as experimental materials and the accuracy of the numerical model is verified by the experimental research of preheating. The optimal preheating strategy of large SLS equipment is confirmed.2 m×2 m nylon 12 powder bed as control object and room temperature difference control in 5 ℃ as the experiment suggests, technological requirements of equipment are met, which provide technical support for the key problem of SLS equipment development and forming precision control.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2018年第7期160-166,共7页
Journal of Mechanical Engineering
基金
国家高技术研究发展计划资助项目(863计划,2015AA042503)
关键词
激光选区烧结
预热均匀性
大尺寸
尼龙12
分区域控制
辐射能系数
selective laser sintering
uniformity of preheating
huge size
nylon 12
subarea control
coefficient of radiant energy
