2001-08-012024-05-18https://scholars.lib.ntu.edu.tw/handle/123456789/699696摘要：本研究針對Ni-Mn-Ga SMAs 38種合金進行線性回歸之分析得：Ms(K)=25.44Ni(at.%)-4.86Mn(at.%)-38.83Ga(at.%),△Hc(J/g)=0.72Ni(at.%)-0.16Mn(at.%)-1.23Ga(at.%)，Ni的at.%的範圍在49.72~54.15 at.%，並依此預測正化合比之Ni2MnGa合金的Ms=184.5K(-88.5oC) 以及△Hc=1.225J/g，且此等合金之變態熱ΔH與其MS溫度間呈線性關係，顯示Ni-Mn-Ga合金具有熱彈型麻田散體變態之性質。本研究以XRD來推測母相及麻田散體相之結構，並由DMA探討該等合金的制震能，發現比Ti49Ni51 SMAs之制震能來得好。接著本研究以VSM、電感和χ-T來探討Ni-Mn-Ga SMAs的磁性行為，其中VSM量測值顯示各合金磁化曲線之磁滯都很小，且母相較麻田散體相容易磁化，此因母相的磁晶異向性較小之故，而電感及χ-T之量測都可明示Tc及麻田散體之變態點。又在Ni-Mn-Ga合金序化程度影響之研究上，發現在600～900℃淬火者對變態溫度的影響都不大。<br> Abstract: Thirty-eight kinds of Ni-Mn-Ga shape memory alloys (SMAs) were investigated in this study. The effects of composition on their Ms temperature and ΔHc can be formulated by the linear regression listed as follows：Ms(K)=25.44Ni(at.%)-4.86Mn(at.%)-38.83Ga(at.%),△Hc(J/g)=0.72Ni(at.%)-0.16Mn(at.%)-1.23Ga(at.%). According to the above eqs. (1), the stoichiometric Ni2MnGa SMA has Ms=-88.5 oC and ΔHc=1.225J/g. The magnetic behaviors of Ni-Mn-Ga SMAs are measured by VSM, inductance tests and χ-T measurements. The saturation magnetization at room temperature obtained from VSM shows that the parent phases have larger magnetization than the martensites with a quite low hysteresis. Furthermore, no obvious effect of quenching temperature is found on the transformation behavior of Ni-Mn-Ga SMAs annealed at 600~900 oC. At the same time, no significant change for the transformation behavior for specimens aged at 400 oC~600 oCx1~120hrs or thermal-cycled for 100 times in between 20 oC and 500 oC. This may imply that the degree of ordering of Ni-Mn-Ga SMAs has not changed by the aforementioned heat-treatings.Ni-Mn-Ga系列形狀記憶合金線性回歸DMA測試序化程度影響時效及熱循環影響Ni-Mn-Ga shape memory alloyslinear regression