高强铝合金的选区激光熔化成形技术基础研究

项目名称： 高强铝合金的选区激光熔化成形技术基础研究

项目编号： No.61475056

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 无线电电子学、电信技术

项目作者： 朱海红

作者单位： 华中科技大学

项目金额： 94万元

中文摘要： 高强Al合金复杂精密构件的需求日益旺盛。选区激光熔化成形技术（Selective Laser Melting，SLM）有望为其提供一种快速整体高精度制造方法。高强铝合金对激光吸收率低、热导率高、易氧化且含大量易烧损合金元素，成形难度大，性能难以控制。本项目通过研究激光与高强铝合金粉末的非定常相互作用过程，揭示高功率密度激光与高强合金粉末相互作用机理；高强铝合金SLM成形的熔池流动特性、非平衡凝固组织特点及冶金缺陷形成机理；成形件的尺寸精度、表面粗糙度的影响因素及控制方法；后续热处理技术及其综合性能评价等关键技术基础，得到SLM加工成形高强铝合金机理和质量控制规律。拟采用N2和Cl2混合气体作为成形气氛、稀薄等离子体的保护作用等方法来消除氧化的危害，利用均匀光束技术控制合金元素的非均匀烧损和浓密等离子体产生、尺寸补偿实现高精度等技术方案，实现高强铝合金的SLM良好成形和性能控制。

中文关键词： 选区激光熔化；铝合金；相互作用；凝固；高强

英文摘要： The demand for fabrication of high strength aluminium components with complex thin wall grows rapidly. Selective laser melting (SLM) is a promising method to provide a rapid integrated manufacturing method for them. Because high strength aluminium alloy is easy to oxidize, has the characteristics of high thermal conductivity, low ionization energy and containing lots of alloying elements which are easy to ablation, fabrication of high strength aluminum alloy parts is very difficult and the properties of the fabricated parts are hard to control. This project is proposed to reveal the key technologies, including the interaction mechanism of laser & aluminium alloy powder, characteritics of the molten pool flowing, solidification microstructure and formation mechanism of metallurgical defects, influencing factors and control method of dimension accuracy and surface roughness, heat treatment technology by investigating the unsteady interaction between laser and Al alloy powder. By using the technolgies, such as, taking the mixture of N2 and Cl2 as process atmosphere, taking the diluted plasma to protect the molten pool and the high temperature metal to eliminate the hazard of oxidization generated in the process, homogenizing the laser energy distribution in the laser spot to reduce the nonuniform burning loss of the alloying elements and control the produce of high density plasma, dimension compensating to realize the high accuracy, the fabrication of Al alloy using SLM is expected to be successful and the properties of fabiration parts is expected to be controlled.

英文关键词： Selective laser melting;Aluminium;Interaction;Solidification;High strength