Controlling Heat Balance in Hot Aluminum Extrusion by Additive Manufactured Extrusion Dies with Conformal Cooling Channels
Controlling Heat Balance in Hot Aluminum Extrusion by Additive Manufactured Extrusion Dies with Conformal Cooling Channels
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DOI：
10.1007/s12541-013-0200-1
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发表时间：
2013-08-01
影响因子：
1.9
通讯作者：
Tekkaya, A. Erman
中科院分区：
文献类型：
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作者：
Hoelker, Ramona;Jaeger, Andreas;Tekkaya, A. Erman
为了防止工件材料过热，采用选择性激光熔化（SLM）增材制造技术设计并制造了一种局部集成冷却的挤压模具。SLM的主要优点是可制造部件的几何自由度，已用于生产具有集成多向通道的冷却介质和集成热电偶的温度测量的模具。为了分析模具冷却对热挤压热平衡的影响，进行了不同冲压速度和坯料预热温度下的挤压试验。压缩空气被用作冷却剂。在较低的滑枕速度下，型材在热铝挤压中的出口温度显著降低，而不会造成挤压力的过度上升。在较高的生产速度下，粗糙表面出现条纹形状的表面缺陷，但可以通过应用内部模具冷却来防止。由于热交换集中在模具轴承的区域上，因此只能观察到冷却对微观结构的影响很小。
To prevent overheating of the workpiece material, an extrusion die with integrated local cooling was designed and manufactured by selective laser melting (SLM) as an additive manufacturing technology. The major advantage of SLM is the geometric freedom of the components that can be manufactured, which has been used to produce a die with integrated multidirectional channels for a cooling medium and the integration of thermocouples for temperature measurement. To analyze the influence of the die cooling on the heat balance in hot extrusion, extrusion trials at different ram speeds and billet preheating temperatures with and without applying die cooling were performed. Compressed air was used as coolant. At lower ram speeds, a significant reduction of the profile's exit temperature in hot aluminum extrusion was achieved without causing an excessive rising of the extrusion force. At higher production speeds, surface defects in the shape of stripes of rough surfaces occurred but could be prevented by applying internal die cooling. Due to focusing of the heat exchange on the area of the die bearings, only a little influence of the cooling on the microstructure can be observed.