摘要
粘结剂喷射3D打印(Binder jet 3D printing,BJP)作为一种增材制造技术,由于能够以高效率和低成本获得复杂结构材料而具有独特的应用价值。然而,实现高致密、高强度金属材料是BJP的一个难题。通过热重分析、金相组织观察、显微硬度测试、致密度和体积收缩率计算、拉伸曲线测试等手段,探究了后处理工艺对粘结剂喷射3D打印316L不锈钢显微组织及力学性能的影响。结果表明,在脱脂阶段,当脱脂温度为600℃、保温时间为120 min时,不同高度的样品脱脂率均保持在4.5%~5.0%之间。在烧结阶段,晶粒尺寸随着烧结温度的升高逐渐增大。在1350℃下烧结,其平均晶粒尺寸为47.27μm。当烧结温度升高到1400℃时,晶粒尺寸增大到51.26μm,且随着烧结保温时间从1 h延长到3 h,晶粒尺寸增大到69.78μm。相应地,316L不锈钢烧结后的致密度从92.20%提高到98.39%,但烧结时间的延长并未提高样品的致密度,这归因于烧结气氛氩气在316L不锈钢中不溶解,当它被困在孔隙中时,压力的增加限制了致密化过程。烧结温度越高,样品强度越高,当样品在1400℃下烧结1 h时,其力学性能最好,此时抗拉强度为536.85 MPa,延伸率为73.74%,继续延长保温时间会由于晶粒尺寸增大以及第二相的增加而使得力学性能降低。
Binder jet 3D printing(BJP),as an additive manufacturing technology,has unique applications due to the ability to obtain complex structural materials with high efficiency and low cost.However,the realization of highly dense,high-strength metal materials is a challenge for BJP.In this work,the effects of post-treatment process on the microstructure and mechanical properties of 316L stainless steel were investigated by means of thermogravimetric analysis,metallographic observation,microhardness testing,density,volume shrinkage calculation,and tensile curve testing.The results show that when the degreasing temperature is 600℃and the holding time is 120 min,the degreasing rate of samples with different heights is maintained between 4.5%and 5.0%.In the sintering stage,the grain size increases gradually with the increase of sintering temperature.Sintered at 1350℃,the average grain size is 47.27μm.When the sintering temperature increased to 1400℃,the grain size increased to 51.26μm,and with the sintering holding time from 1 h to 3 h,the grain size increased to 69.78μm.Correspondingly,the density of 316L stainless steel after sintering increased from 92.20%to 98.39%,but the extension of sintering time did not improve the density of the sample,which is attributed to the sintering atmosphere of argon in 316L stainless steel does not dissolve.When it is trapped in the pores,the increase in pressure limits the densification process.The higher the sintering temperature,the higher the strength of the sample.When the sample is sintered at 1400℃for 1 h,the mechanical properties are the best,and the tensile strength is 536.85 MPa and the elongation is 73.74%.The mechanical properties will be reduced due to the increase of grain size and the increase of the second phase if the holding time is continued.
作者
剡秀秀
王勇
严生辉
罗凯
刘于青
何玉玉
张芸芸
李天才
曹继伟
YAN Xiuxiu;WANG Yong;YAN Shenghui;LUO Kai;LIU Yuqing;HE Yuyu;ZHANG Yunyun;LI Tiancai;CAO Jiwei(Kocel Intelligent Machinery Limited,Yinchuan 750021,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2024年第S01期473-478,共6页
Materials Reports
关键词
316L不锈钢
粘结剂喷射3D打印
脱脂烧结
力学性能
316L stainless steel
binder jetting 3D printing
debinding and sintering
mechanical property
