大型薄壁件熔融成形数值计算与工艺实验研究  

Numerical Simulation and Experimental Research of Fused Deposition for Forming Large-Size Thin-Walled Parts

作　　者：杜军[1] 魏正英[1] 王鑫[1] 王吉洁 

机构地区：[1]西安交通大学机械制造系统工程国家重点实验室,陕西西安710049

出　　处：《机械设计与制造》2016年第8期86-89,93,共5页Machinery Design & Manufacture

基　　金：陕西省自然科学基金项目(2014JQ7238)

摘　　要：针对熔融挤出成形大型薄壁件时易出现变形、开裂的问题,提出采用激光束对成形区进行辅助加热以提高成形质量和精度。采用计算流体动力学方法建立熔融挤出成形过程数值计算模型,对熔融挤出成形特征区域温度历程及三维形貌特征进行分析与实验验证。研究了成形速度、激光功率、激光辅助加热方式对成形区聚合物熔体表面温度及粘度的影响。研究结果表明采用侧向激光辅助加热方式比前后置激光辅助加热方式对粘接区域表面温度提升更高;采用激光辅助加热显著提高了薄壁件抗拉强度,其最大提高幅度可达195%;采用激光辅助加热后,成形件表面粗糙度有所降低,层间粘接宽度比先前提高近24%。Aiming at the problem of deformation and cracking during the fabrication of large-size thin-walled parts, an improved fused deposition modeling process with loser assisted heating was put forward to improve forming quality and accuracy. The numerical model of the improved process was established to analyze the temperature history and three- dimensional morphology during the forming process. The numerical model was verified by experiments from two aspects： the temperature information and the three-dimensional morphology. The effects of the forming speed,the loser power and the ways of loser heating on the surface temperature and viscosity of the forming material was investigated. The results show that thelateral loser heating has more obvious effect in the temperature increases of the surface regions than the pre- and post- loser heating. The tensile strength of the thin-walled parts was increased by 195% when the loser assisted heating Was employed. Meanwhile ,the surface roughness of the parts was reduced and the effective bonding width between layers was almost higher than previously formed by 24%.

关 键 词：大型薄壁件 熔融挤出成形 激光辅助加热 三维形貌 抗拉强度 

分 类 号：TH16[机械工程—机械制造及自动化] O373[理学—流体力学]