The Isothermal Sections Of The Mn-Si-TM(TM=Ni,Zr,Ti)Ternary System At600℃

Mn, Ni, Si, Zr and Ti are the important alloying elements in steel and aluminum alloys. Due to the interaction among the alloying elements, Steel and aluminum alloys characterized comprehensive unique mechanical properties. The knowledge for the interaction among the alloying elements, would provide good guidance to improve the performance of the alloys. In this work, the isothermal sectional of the Mn-Ni-Si, Mn-Zr-Si and Mn-Ti-Si ternary systems at600℃were experimentally investigated by X-ray diffraction, scanning electron microscope and energy dispersive analysis. Some important results are summarized as follow:(1) The phase equilibria of the Mn-Ni-Si ternary system at600℃were established. Mn6Ni16Si7(T), Mn15Ni40Si45(N), MnNiSi(E), Mn3Ni3Si2(Г1), Mn2Ni3Si(Г2) and Mn3Ni2Si(Q) compounds were stable at this temperature, while compound Mn15Ni50Si35(Φ), Mn45Ni40Si15(τ), Mn61Ni,2Si27(R) and Mn66Ni4Si30(U) were not observed in this work. The maximum solubility of Ni in MnSi was determined to be35at.%.(2) The isothermal section of the Mn-Zr-Si ternary system at600℃were determined for the first time. A new termary compound was discovered in the present work. This compound was found to be isostrutural to Fe4Si7Zr4with hexagonal structure and cell parameters of a=1.3027nm, c=0.515nm. A quite different conclusion was obstained for the Zr-Si binary system at the present work comparing to results in the literatures. Currently, there was no the evidence to support the existence of Zr3Si, which was taken as a stable phase in the Zr-Si system, moreover, XRD and SEM/EDS revealed that Zr5Si3was a stable phase. In addition, MnSi2Zr and MnSiZr ternary compounds were observed stablly in this system at600℃.(3) The isothermal section of the Mn-Ti-Si system at600℃was established in the whole composition range. Ti5Si4was observed to be stable in the Ti-Si binary system, while Ti3Si was not found in this work. In present work, four ternary compounds:MnTiSi, MnSi2Ti, Mn4Si5Ti2and MnSi4Ti were detected. The Mn16Si3Ti phase, which stable at1000℃, was not observed at the temperature of600℃.