激光烧结制备CrFeNiAlSiTix高熵合金组织与性能

Microstructure and properties of CrFeNiAlSiTix high entropy alloy prepared by laser sintering

摘要:

为了验证利用铬铁矿粉直接制备高熵合金的可行性，选取和天然铬铁矿粉成分接近的Cr、Fe、Ni、Al、Si作为基础元素，向其掺杂非等摩尔比的Ti元素混合后压制成坯，采用激光自蔓延烧结制备CrFeNiAlSiTix（x=0-1.2）高熵合金。通过共聚焦显微镜、XRD、SEM和EDS、维氏显微硬度计、电化学工作站等进行表征，分析物相结构、显微组织、密度和孔隙率、硬度、耐磨、耐蚀及高温氧化性能。结果表明：随着Ti含量的增加，合金中BCC相增多，且通过本征参数计算进行验证与实验结果吻合。树枝晶组织减少，花瓣状组织增加，枝晶中主要存在与Ti结合力强的元素。当x=1.0时，合金显微硬度最大为935.62 HV，密度最大为5.01 g/cm3，孔隙率最小为24.01 %，单位面积磨损量最小为34 mg·cm-2，氧化速率最大为5.92×10-6 mg2·cm-4·s-1，腐蚀电流为0.98 μA/cm2，年腐蚀深度为1.01×10-2 mm/a。

Abstract:

In order to verify the feasibility of directly preparing high entropy alloy using natural ferrochrome ore powder, Cr, Fe, Ni, Al, Si close to the ferrochrome ore powder was selected as the base element and suppressed into billet after mixed with Ti elements doped with non-equimolar ratio, and CrFeNiAlSiTix (x=0-1.2) high entropy alloy was prepared by laser self-spreading sintering. It was characterized by OM, XRD, SEM and EDS, Vickers microhardness tester and electrochemical workstation, and its phase structure, microstructure,density and porosity, hardness, wear resistance, corrosion resistance and high temperature oxidation properties were analyzed. The results show that with the Ti content, the alloy increases BCC phase and confirms the results of intrinsic parameters.The results show that the Ti content and the experimental parameters are consistent with the experiment. Dendritic tissue decreases, petal-like tissue increases, and elements with strong Ti binding forces are mainly present in dendritic crystals. When x=1.0, the maximum alloy microhardness of 935.62 HV, maximum density of 5.01 g/cm3, porosity of 24.01%, minimum per area wear of 34 mg·cm-2, oxidation rate of 5.92×10-6 mg2·cm-4·s-1, corrosion current of 0.98 μA/cm2, annual corrosion depth of 1.01×10-2 mm/a..