CAJ | 학술논문

通过控制Ni基自熔性合金粉末中Al的含量，在H13热作模具钢表面分别原位制备了Ni3Al和NiAl金属间化合物复合熔覆涂层。借助光学显微镜和X射线衍射仪对不同熔覆涂层的化学组成和物相结构进行了分析。结果表明，四种不同Al含量的熔覆层均显现出平整致密、无明显缺陷的宏观特征。随着Al含量的增加，熔覆层显微形貌呈现出底部枝晶区域增加及枝晶逐渐粗化，甚至出现胞状晶的现象。熔覆层在未加入Al时，其主要物相为Ni3Fe及(Ni, Cr)固溶体。随着Al含量的增加，主要物相则由最初的Ni3Al金属间化合物、(Ni, Cr)固溶体到Ni3Al、NiAl金属间化合物和(Fe，Cr)固溶体，再到最终Al含量达到13.9%时的NiAl金属间化合物和(Fe，Cr)固溶体。同时，Al含量的提高使得涂层中杂质相减少。熔覆层摩擦系数均低于基体，最高显微硬度为基体的3.5倍，耐磨性较基体提高了5.8倍。
통과공제Ni기자용성합금분말중Al적함량，재H13열작모구강표면분별원위제비료Ni3Al화NiAl금속간화합물복합용복도층。차조광학현미경화X사선연사의대불동용복도층적화학조성화물상결구진행료분석。결과표명，사충불동Al함량적용복층균현현출평정치밀、무명현결함적굉관특정。수착Al함량적증가，용복층현미형모정현출저부지정구역증가급지정축점조화，심지출현포상정적현상。용복층재미가입Al시，기주요물상위Ni3Fe급(Ni, Cr)고용체。수착Al함량적증가，주요물상칙유최초적Ni3Al금속간화합물、(Ni, Cr)고용체도Ni3Al、NiAl금속간화합물화(Fe，Cr)고용체，재도최종Al함량체도13.9%시적NiAl금속간화합물화(Fe，Cr)고용체。동시，Al함량적제고사득도층중잡질상감소。용복층마찰계수균저우기체，최고현미경도위기체적3.5배，내마성교기체제고료5.8배。
In situ Ni3Al and NiAl intermetallic compound composite laser cladding coatings were prepared on H13 hot die steel surface by controlling Al content in the Ni- based self- fluxing alloy powder. The chemical composition and phase structure of the different laser cladding composite coatings were characterized by optical microscopy (OM) and X- ray diffraction (XRD). The results indicate that the four kinds of composite laser cladding coatings all show a smooth, dense and without obvious defects macroscopic morphology. The dendrite region becomes wider and the dendrite size gradually becomes thicker in the laser cladding coatings bottom with the increase of Al content, even a columnar crystal phenomenon can be found. Without Al, the main phase of the composite coating is Ni3Fe and Ni- Cr solid solution. While with the increase of Al content, the main phase changes from Ni3Al intermetallic compound and Ni- Cr solid solution to Ni3Al+NiAl intermetallic compound and Fe- Cr solid solution, and then to NiAl intermetallic compound and Fe- Cr solid, when the Al content increases to 13.9%. At the same time, the impurity phase in laser cladding coating decreases with the increase of the Al content. The cladding coatings friction coefficients are lower than those of the H13 steel substrate. The highest microhardness of the coating increases by 250% and the abrasion resistance increases by 480%respectively.