摘要
SLM(激光选区熔融)原位合金化技术,即原材料采用混合单质粉末在激光选区熔融过程中直接完成元素合金化并同步成型高致密度样件的方法。该技术可省掉原料粉末预合金化过程,通过实时、定量粉末混合给料控制,可实现块体样品的高通量制备。将SLM合金化与高通量制备两者有机融合应用于特种材料体系如高熵合金等材料的开发,实现材料成分、结构、物理化学性质的高通量获取,可为材料设计和制备技术的发展提供一项颠覆性的创新手段,科学意义和应用价值巨大。基于自主设计开发的SLM高通量制备系统,采用铁、镍单质元素粉一次性制备12组Fe-Ni合金块体样品,采用CALPHAD方法计算了铁镍合金的相图及密度,通过金相扫描、能谱、XRD、显微硬度试验等方法分析设备的实时混粉精度和样件的成型性能。计算和实验结果显示,基于自研高通量SLM设备的粉末成分混合精度可控制在6%(质量分数)以内。样品成型性能良好,致密度均在98.5%以上,金相组织中未见明显的孔洞、未熔合和未熔颗粒。随着镍含量变化,高通量打印样品硬度在150~330HV之间变化,未见明显的硬度离散分布,设备打印功能稳定可靠。
SLM(selective laser melting) in-situ alloying technology is a method in which the pure element powder blend is alloyed directly and high density samples are formed synchronously in the process of SLM. This technology can save the pre-alloying process of raw material powder and achieve high-throughput bulk sample preparation by real-time and quantitative powder mixed feeding control. Researchers can obtain material data of composition, structure, properties effectively with the combined SLM alloying and high throughput synthesis technology. The development of new material such as high entropy alloys and other novel materials can be promoted effectively once the technology is available, hence, there are both great scientific significance and application value. Based on the self-designed SLM high-throughput preparation system, 12 groups of Fe-Ni alloy bulk samples were prepared by real-time quantitative mixing of iron and nickel elemental powders and SLM printing in present work. The density and phase transition of homogeneous Fe-Ni alloy were calculated by CALPHAD method. The powder mixing accuracy of the equipment and the forming performance of the samples was analyzed by metallographic observation, energy spectrum, XRD and microhardness test. The calculation and experimental results showed that the mixing accuracy of powder composition based on self-developed high-throughput SLM equipment could be controlled within 6 %(mass percentage). All samples were fabricated with good forming quality, and the relative density were above 98.5 %. There were no obvious holes and no fusion in the microstructure. The micro-zone alloying of all samples was basically completed during SLM printing. The hardness of mixed powder samples varied from 150 HV to 330 HV, and there was no obvious discrete distribution of hardness caused by equipment instability.
作者
侯雅青
苏航
张浩
王炫东
王畅畅
HOU Yaqing;SU Hang;ZHANG Hao;WANG Xuandong;WANG Changchang(Department of Structural Steels,CISRI,Beijingl00081,China;Material Digital R and D Center,CISRI Group,Beijing 100081,China;Beijing MatDao Technology Co.,Ltd.,Beijing 100081,China;ADRAYN Technology Co.,Ltd.,Chongqing 404100,China)
出处
《金属功能材料》
CAS
2021年第4期50-58,共9页
Metallic Functional Materials
基金
材料基因工程关键技术与支撑平台国家重点研发计划项目(2017YFB0701802)。
关键词
高通量制备
激光选区熔融
热动力学计算
铁镍合金
激光原位合金化
high-throughput synthesis
selective laser melting
thermodynamic calculation
iron-nickel alloys
SLM in-situ alloying
