INFLUENCE OF PROCESSING ON SHAPE MEMORY EFFECT OF Fe-Mn-Si-Ni-C-RE SHAPE MEMORY ALLOY

Effect of carbon, compound RE, quenching temperature, pre-strain and recovery temperature on shape memory effect (SME) of Fe-Mn-Si-Ni-C-RE shape memory alloy was studied by bent measurement, thermal cycle training, SEM etc. It was shown that the grains of alloys addition with compound RE became finer and SME increased evidently. SME of the alloy was weakening gradually as carbon content increased under small strain (3%). But in the condition of large strain (more than 6%), SME of the alloy whose carbon content range from 0.1% to 0.12% showed small decreasing range, especially of alloy with the addition of compound RE. Results were also indicated that SME was improved by increasing quenching temperature (>1000℃). The amount of thermal induced martensite increased and the relative shape recovery ratio could be increased to more than 40% after 3-4 times thermal training. The relative shape recovery ratio decreased evidently depending on rising of pre-strain. Furthermore, because speed of martensite transi     

CuZnAl形状记忆合金弹簧的应用研究

应用CuZnAl形状记忆合金的感温-驱动原理,制作了太阳尾随模拟装置,探讨了该系统中形状记忆合金弹簧的设计原理及方法。同时采用定量金相、电子探针、电阻法、X射线衍射等方法,研究了加入复合稀土及热处理工艺对CuZnAl形状记忆合金中马氏体稳定化的影响。实验结果表明,形状记忆合金弹簧材料的应力-应变曲线是非线性的,弹性模量等不是常数,而是随温度变化的,所以设计原理主要考虑温度的因素,并对防止发生马氏体稳定化的原因进行了论述。     

热循环对Fe-Mn-Si-Cr-Ni合金形状记忆效应的影响

采用电阻法和OM等手段研究了不同温度区间的热循环对Fe-14Mn-5.5Si-8Cr-5Ni合金微观组织和形状记忆效应的影响。结果表明:298 K～353 K、520 K、773 K和77 K～773 K热循环1次后,合金形状回复率均大幅度提高;298～773 K循环5次后的形状回复率提高了26%,77～773 K热循环5次后的形状回复率提高了36%。热循环显著减少了因淬火热应力导致的热诱发ε马氏体量,并且热诱发ε马氏体的逆转变向基体引入了大量的堆垛层错。与固溶态相比,热循环后再变形不仅使α’马氏体的数量显著减少,而且应力诱发ε马氏体以区域化的方式形成,因而合金的形状记忆效应显著提高。77～773 K的热循环比298～773 K的热循环更能显著提高合金形状记忆效应的原因是由于其引入了更多的堆垛层错。     

铸态FeMnSiCrNi合金的形状记忆效应

分别研究了预变形量对超低碳与含0.12%碳的铸态FeMnSiCrNi形状记忆合金的形状记忆效应的影响,并将以上结果与冷拉FeMnSiCrNi形状记忆合金的结果进行了比较。结果表明:预变形量小于5%时,两种铸态合金的形状记忆效应基本不变;而预变形量大于5%时,随预变形量的增加形状记忆效应降低。当预变形量相同时,含0.12%碳的合金的形状记忆效应低于超低碳合金。预变形量为5%时,超低碳与含0.12%碳的合金的形状回复率分别达到73%、62%,具有与冷拉FeMnSiCrNi丝相当的形状记忆效应。     

CuZnAl形状记忆合金磨损性能试验研究

对CuZnAl形状记忆合金采用不同热处理工艺处理后,在不同载荷、不同磨损时间、不同摩擦副条件下进行了干磨损和油润滑动磨损试验。同时与锡青铜和铝铁青铜进行了对比试验,并用电子扫描显微镜对磨损表面和磨屑进行了观察。结果表明:CuZnAl形状记忆合金在干磨损条件下,两级时效处理的合金耐磨性能优于分级淬火处理的合金,而在油润滑动磨损条件下,分级淬火处理的合金耐磨性能优于两级时效处理的合金。CuZnAl形状记忆合金的耐磨性能优于锡青铜和铝铁青铜。用CuZnAl形状记忆合金组成的摩擦副,其耐磨性优于用45#钢与形状记忆合金组成的摩擦副。     

EFFECT OF DYNAMIC RECRYSTALLIZATION ON SHAPE MEMORY EFFECT IN Fe－Mn－Si BASED ALLOYS

ＥＦＦＥＣＴＯＦＤＹＮＡＭＩＣＲＥＣＲＹＳＴＡＬＬＩＺＡＴＩＯＮＯＮＳＨＡＰＥＭＥＭＯＲＹＥＦＦＥＣＴＩＮＦｅ－Ｍｎ－ＳｉＢＡＳＥＤＡＬＬＯＹＳ￥Ｌ．Ｊ．Ｒｏｎｇ;Ｙ．Ｙ．ＬｉａｎｄＣ．Ｘ．Ｓｈｉ（ＩｎｓｔｉｔｕｔｅｏｆＭｅｔａｌＲｅｓｅａｒｃｈ,Ｃ...     

Effect of chemical component on shape memory effect of Fe-Mn-Si-Ni-C-RE shape memory alloy

Effect of chemical component on shape memory effect (SME) of Fe-Mn-Si-Ni-C-RE shape memory alloys was studied by bent measurement, thermal cycle training, SEM etc. Results of study indicate that the alloys with high Mn content (25%) appeare better SME, especially in lower strain. SME improves evidently when Si is higher content, especially it's range from 3% up to 4%. But brittleness of Fe-Mn-Si-Ni-C-RE alloy increases by increasing the Si content. SME of the alloy is weakening gradually as carbon content increases under small strain (3%). But in the condition of large strain (above 6%), SME of the alloy whose carbon content ranges from 0.1 % to 0.12% shows small decreasing range, especially of alloy with the addition of compound RE.     

相变温度对CuZnAl形状记忆合金干磨损性能的影响

研究了相变温度对复合细化后的CuZnAl形状记忆合金干滑动摩损性能的影响,结果表明：同样的热处理工艺,在摩擦副温升不大时高温相变合金比低温相变合金耐磨,摩擦副温升较大时,低温相变合金耐磨性优于高温相变合金。合金的磨损失重机制为粘着磨损、剥离磨损和犁削磨损。     

电脉冲处理对不同预变形量Fe17Mn5Si8Cr5Ni0.5NbC合金NbC析出相与形状记忆效应的影响(英文)

为进一步提高铁基形状记忆合金的记忆效应并改善处理技术,研究了电脉冲处理对不同预变形量Fe17Mn5Si8Cr5Ni0.5NbC合金性能的影响。结果表明:当预变形量低于 10%时,电脉冲处理后合金的形状回复率随着预变形量的增大而增大,且最大值比800 °C热处理的合金高 8%左右。与热处理状态相比,当预变形量低于10%时,随着预变形量的增大,电脉冲处理诱导出NbC颗粒的数量更多、尺寸更小、析出速度更快,进而有效改善合金的记忆性能。     

真空感应重熔NiTi形状记忆合金室温拉伸力学性能

采用真空感应熔炼炉制备NiTi合金,并对重熔后的合金进行不同制度热处理。研究NiTi形状记忆合金边角料重熔合金不同温度时效后的室温拉伸力学性能。结果表明,NiTi形状记忆合金边角料重熔后,其室温屈服强度和抗拉强度均有不同程度的提高,断后延伸率略有增加,应力诱发马氏体相变对应的形状回复率降低;合金塑性变形能力随时效温度的升高而变差;合金中R相重新取向所提供的延伸率从总体上看比由单质原材料一次熔炼而成的合金要高。     

DRY SLIDING WEAR OF Cu-BASED SHAPE MEMORY ALLOY

The wear of Cu-based CuZnAl shape memory alloys under dry sliding against steel wasfound to be plasticity-dominated,with adhesion and delamination being the two main mecha-nisms.Adhesion was found to be accompanied by metal transfer.TEM observation on tensiletest of thin foil showed that the stress-induced martensitic transformation occurred fromβ-phase in the vicinity of pre-existing microcracks.The blunt effect of crack tips may beproposed to explain the wear of CuZnAl shape memory alloy due to preferential orientationreaction of variants in martensite and stress-induced martensitic transformation in β-phase.     

TiNi合金的形状记忆效应及其工程应用研究进展

对TiNi合金形状记忆效应（SME）的特性、影响因素和工程应用的研究现状进行了综述。着重介绍了TiNi合金SME的特点及其工程意义,合金成分、热处理和加工工艺对SME的影响,以及TiNi合金在驱动器、连接器和紧固件制作,结构变形和开裂控制,结构振动主动控制等方面的应用,并就目前研究的不足以及该研究领域的发展方向提出了一些看法。     

热诱发ε马氏体量对Co-30Ni合金形状记忆效应的影响

为了明确具有ε马氏体转变的Co-Ni基合金形状记忆效应的来源,通过控制不同变形温度,在Co-30Ni合金中获得不同数量的热诱发ε马氏体,在此基础上利用OM和XRD研究了变形时预先存在的热诱发ε马氏体的演化及其对应力诱发ε马氏体转变的影响,并采用弯曲法表征了合金的形状记忆效应。结果表明:合金的形状记忆效应都随热诱发和应力诱发ε马氏体数量的增加而升高,但原位金相未观察到热诱发ε马氏体在应力下的长大合并。Co-Ni基合金的形状记忆效应来源于应力诱发ε马氏体转变,而不是热诱发ε马氏体在应力下的长大合并。低的母相屈服强度是Co-Ni合金形状记忆效应差的原因。预先形成的热诱发ε马氏体能提高母相的屈服强度,因而有利于形状记忆效应的提高。     

EFFECT OF γ-IRRADIATION ON CuZnAl SHAPE MEMORY ALLOY

Effect of γ-irradiation on the shape memory alloy CuZnAl has been studied by the techniquesof TEM,positron annihilation etc..The martensitic transformation temperature of the alloyincreases obviously ofter γ-irradiation at a dose of 2×10~7 Gy but not for a dose of 1×10~7 Gy.The shape memory effect in both irradiated alloys remains unaffected.     

Co对Ti-Ni形状记忆合金相变和形变特性的影响

用热重分析仪、X射线衍射仪、示差扫描量热仪及拉伸试验研究了Co对Ti-49.8Ni(at%,下同)形状记忆合金相变和形变特性的影响。结果表明,中温退火态Ti-49.8Ni合金冷却/加热时的相变类型为A→R→M/M→A(A—母相,R—R相,M—马氏体相);随退火温度升高,该合金的马氏体相变温度升高,R相变温度先升高后降低;该合金室温相组成为马氏体,具有形状记忆效应(SME)。用1%Co置换等量Ti后所得Ti-49.8Ni-1Co合金冷却/加热时的相变类型为A→R→M/M→R→A,相变温度低,室温组成相为母相A,具有超弹性(SE)特性。退火温度低于600℃时,Ti-Ni基合金的SME和SE特性良好,退火温度超过600℃后,合金氧化加剧,SME和SE特性变差,塑性显著提高。     

Effects of thermomechanical cycling on the shape memory behavior and transformation temperatures of a Ni50.2Ti49.8 alloy

The effects of thermomechanical cycling on the shape memory behavior and transformation temperatures of a Ni50.2Ti49.8 alloy under a constant applied stress of 300 MPa were investigated.It is believed that thermomechanical cycling induces defects such as dislocations,which evidently affect the shape memory behavior and transformation temperatures.The recovery strain decreases with increasing number of thermomechanical cycles,whereas the irreversible plastic strain increases,especially in the initial few cycles.The stored elastic strain energy has an important influence on transformation temperatures,the Aso decreases and the Mso increases with increasing number of thermornechanical cycles.The recovery strain,irreversible plastic strain,Aso,and Mso reach a saturation value after several cycles.     

Role of thermal martensite in shape memory effect of CoAl and CoNi alloys

To address the role of the HCP martensite in CoAl and CoNi shape memory alloys, the relationship between the shape memory effect (SME) and the content of the thermal and stress-induced HCP martensite was investigated in the solution-treated CoAl and CoNi alloys. In-situ optical observations were employed to investigate the contents of thermal HCP martensite before and after deep cooling and its influence on the stress-induced HCP martensite transformation and SME. The results show that the SME in both the CoAl and the CoNi alloys results from the stress-induced HCP martensite. The role of the thermal HCP martensite in both of them is the strengthening of the matrix. The much higher yield strength in the solution-treated CoAl alloy due to solution strengthening of Al is responsible for its better SME compared with the CoNi alloy.     

Influence of roll and solution treatment processing on shape memory effect of Fe-14Mn-5Si-9Cr-5Ni alloy

The shape memory effect was studied in an Fe-14Mn-5Si-9Cr-5Ni alloy rerolled at 1123 K after hot rolling at 1423 K, followed by solution treatment at different temperatures. It was found that the alloy exhibits a maximum degree of shape recovery in a bending test and a complete recovery tensile strain of 2.2% in samples that were solution heated at 973 K for 600 s and then quenched in water. The rerolled processing at 1123 K after hot rolling at 1423 K and the microstructure under solution treatment state are important for obtaining a good shape memory effect in the alloy.     

两种不同变形方式对NiTi合金回复特性的影响

研究了马氏体再取向(MR)和应力诱发马氏体转变(SIM)两种不同变形方式对Ni50.2Ti49.8合金拉伸性能及预应变后加热回复特性的影响.结果表明:拉伸变形中,MR变形方式的应力平台结束时的应变值较SIM变形方式大.在拉伸预应变处于应力平台阶段时,两种变形方式在相同预应变后加热回复有相同的记忆能力;在拉伸预应变大于应力平台时,两种变形方式在相同预应变后加热回复,SIM变形方式的逆相变温度和回复应变略高于MR变形方式.     

中国钛工业概览

采用弯曲和循环拉伸实验研究了新型Ti-3Zr-2Sn-3Mo-15Nb(TLM)钛合金的形状记忆和超弹性性能.探讨了变形温度、总应变和热处理等对TLM钛合金形状记忆和超弹性的影响规律.结果表明:新合金在热轧态和在α β两相区固溶处理后空冷比从β相区固溶处理后空冷条件下具有较高的形变恢复率,最大恢复应变可达1.8%.随着总变形应变增加,形变恢复率降低.从β相区固溶处理后空冷后TLM合金具有较好的超弹性,优于热轧态或时效处理后TLM合金的超弹性能.