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1.
用XRD(X射线衍射)和HRTEM(高分辨透射电镜)研究了高能球磨Fe70Ni30二元金属合金的微结构随球磨时间(t)的变化情况。结果表明:以羰基铁和羰基镍为原料,通过高能球磨得到了bcc结构FeNi纳米晶合金。球磨10h时,羰基铁和羰基镍开始形成合金,但大部分R、Ni原子仍分别以bcc结构和fcc结构存在。球磨100h时,样品以bcc结构的FeNi合金为主,球磨200h后,样品中fcc结构Ni特征峰几乎消失,FeNi纳米晶达到最小粒径的平衡值。~8nm。高能球磨过程中,晶界区域的层错缺陷是合金化和纳米晶形成的重要因素.  相似文献   

2.
Thermoelectrical properties of (FeNi)xCo4-xSb12 prepared by MA-SPS   总被引:2,自引:1,他引:1  
Bulk skutterudite (FeNi)xCo4-xSbl2 with x varying from 0.05 to 1.0 were prepared by mechanical alloying and spark plasma sintering (MA-SPS). The phases of the samples were analyzed by X-ray diffraction, and their thermoelectrical properties were tested by electrical constant instrument and laser thermal constant instrument. The experimental results show that bulk (FeNi)xCo4-xSb12 have the characteristic of typical semiconductor electricity. The addition of FeNi improves the electrical properties to a large extent; the samples of bulk (FeNi)xCo4-xSbl2 (x = 0.05-1.0) are n-type semiconducting materials; the increase of FeNi content can decrease the absolute value of Seebeck coefficient and therefore decrease the ZT value; FeNi with a higher content when x 〉 0.5 leads to an evident increase in thermal conductivity and also a decrease in ZT value. In general, for ZT value, the optimal added content of FeNi is 0.25-0.5 and the maximum ZT value is 0.2467 when x = 0.5 at 500℃.  相似文献   

3.
采用两步法氧乙炔火焰喷焊技术对某化工厂一种专用柱塞进行修复强化,喷焊层材料为Ni60自熔性合金粉末,并进行了工艺试验和硬度试验.结果表明:喷焊层的硬度明显提高;该修复强化工艺可满足柱塞的技术使用要求,该工艺质量高、成本低,对柱塞表面修复强化具有广泛的应用前景.  相似文献   

4.
对16Mn钢表面氧乙炔火焰喷焊自熔性铁基及镍基合金粉末得到铁基合金喷焊层和镍基合金喷焊层,并对两种喷焊层进行了显微组织,组成相,硬度和耐磨性以及抗热疲劳性能的比较研究,结果表明,两种堆焊层组织都具有枝晶生长特征,枝晶间存在着共晶组织,两种涂层均由γ固溶体和多种共晶化合物相组成,但镍基合金喷焊层的枝晶比较细小,镍基合金喷焊层比较基合金喷焊层具有较高的硬度和耐磨性,同时也具有较好的抗热疲劳性能。  相似文献   

5.
Laser cladding of Ni-based alloy on copper substrate   总被引:7,自引:0,他引:7  
The laser cladding of Ni1015 alloy on Cu substrate was prepared by a high power continuous wave CO2 laser. Its microstructure was analyzed by optical microscope (OM), scanning electron microscope (SEM), and X-Ray diffraction (XRD). The average microhardness of the cladding coating was Hv 280, which was almost three times of that of the Cu substrate (Hv 85). OM and SEM observations showed that the obtained coating had a smooth and uniform surface, as well as a metallurgical combination with the Cu substrate without cracks and pores at the interface. With the addition of copper into the nickel-based alloy, the differences of thermal expansion coefficient and melting point between the interlayer and cladding were reduced, which resulted in low stresses during rapid cooling. Moreover, large amount of (Cu, Ni) solid solution formed a metallurgical bonding between the cladding coating and the substrate, which also relaxed the stresses, leading to the reduction of interfacial cracks and pores after laser cladding.  相似文献   

6.
TiNi基形状记忆合金弹簧是一种有广阔应用前景的形状记忆合金驱动元件.研究了在电流加热方式下,不同加热温度,不同恒载荷作用下TiNi和TiNiCu记忆合金弹簧的热稳定性.研究表明,恒定载荷下,最初的几次循环后,弹簧的行程变小,而在循环次数超过一定次数后,弹簧的行程不随着循环次数的增加而发生明显变化.对于TiNi和TiNiCu记忆合金弹簧,过热和过载均会向弹簧中引入不可逆的塑性变形,导致其热稳定性的下降.由于Ti3Ni4相粒子的析出强化了基体,在恒载荷下,TiNi合金弹簧较TiNiCu合金弹簧显示出更加良好的热稳定性.  相似文献   

7.
采用涂盐法,在纯Ni、Ni-10Cr、Ni-20Cr和Ni-10Cr-5Al合金上涂敷40~ 45 g/m2厚度Na2SO4盐膜,研究其在900℃空气中的热腐蚀行为.结果表明:纯Ni和3种Ni基合金的抗热腐蚀性能依纯Ni、Ni-10Cr-5Al、Ni-10Cr、Ni-20Cr的次序递增.3种Ni基合金形成了相似的腐蚀膜结构,腐蚀膜大体分3层,外层都是NiO.Ni-20Cr合金中间层为连续的Cr2O3层,内部出现极少的硫化物;Ni-10Cr合金腐蚀膜的中间层是相对深色的NiO和Cr2O3混合层,内侧出现硫化物;而Ni-10Cr-5Al合金腐蚀膜的中间层是NiO、Cr2 O3和Al2O3的混合氧化物,内层是Cr和Al的硫化物,分布在腐蚀膜和基体的界面上,有的分布在合金基体上.在Ni的基础上添加Cr并增加Cr含量均提高了合金的抗热腐蚀性能,但在Ni-10Cr的基础上增加质量分数5%Al却使抗热腐蚀性能下降.  相似文献   

8.
为了分析Al-Ni-Y三元合金的玻璃形成能力和热稳定性,采用熔体急冷法制备了Al90Ni2Y8、Al87Ni5Y8、Al84Ni8Y8和Al80Ni12Y8合金条带.利用x-射线衍射(XRD)表征了急冷态和部分晶化后条带的结构,运用示差扫描量热仪(DSC)分析了合金的玻璃转变和晶化行为.结果表明:除了Al80Ni12Y8和Al90Ni2Y8合金外,制备态的条带均为完全非晶态,部分晶化后有纳米铝晶体析出;Al84Ni8Y8合金DSC曲线上可以明显地观察到玻璃转变温度Tg.〖JP2〗通过比较4种合金的热稳定性,发现随着Ni的原子分数升高,合金的初始晶化温度Tx也随着升高,合金的热稳定性增强.  相似文献   

9.
三种Ni-WC合金粉末喷焊层耐磨性的研究   总被引:1,自引:0,他引:1  
以Ni60自熔合金为喷焊材料,通过对喷焊层组织、硬度及磨损形式进行分析,探讨了Ni60、Ni60 20%WC、Ni60 35%WC三种合金粉末喷焊层耐磨性,对三种Ni60粉末喷焊层的干磨损、腐蚀磨损行为进行了研究。结果表明,合金粉末WC含量升高时,喷焊层耐磨耐蚀性提高。  相似文献   

10.
基于嵌入原子法并采用最近邻模型,推导出改进的嵌入原子法势函数形式,计算了FCC结构FeNi合金晶格常数与团溶度的关系,其结果与实验吻合.根据能量稳定性原理,采用优化的方法,计算了不同团溶度下合金的电荷转移情况.  相似文献   

11.
IN909低膨胀高温合金具有较低的热膨胀系数和高的综合力学性能,但由于合金不含Cr,其抗氧化性能较差,因此,在高温使用时需采用氧化涂层.为进一步提高合金的抗氧化性能,采用扫描电镜(SEM)和能谱分析(EDX)方法,研究了低膨胀IN909合金在650℃的氧化行为,结果显示IN909合金的氧化质量增加分段遵循抛物线规律,氧化由晶界开始,形成Nb、Ti、Si等元素的晶界氧化物;Fe置换氧化物中的Nb、Ti、Si,形成外层Fe的氧化物.氧化过程中,Fe由基体向合金表面扩散,Nb和Ti由氧化过渡层向基体扩散.Nb和Ti在基体前沿的富集形成ε相大量析出的薄层,可有效地阻碍Fe元素的进一步扩散,降低氧化速率.  相似文献   

12.
采用单辊甩带技术制备出的铝基非晶合金Al88Ce8Ni4,利用XRD、TEM和DSC对非晶热稳定性和晶化行为进行了分析,结果表明,该所制备的铝合金属于完全非晶态,开始晶化温度达到(Tx)530K,其稳定性良好.晶化过程分两步进行,且晶化产物除了初生相α-Al,大多以Al-Ce和Al-Ni原子簇组成.  相似文献   

13.
基于由第一性原理计算的结合能曲线经过晶格反演获得的原子间相互作用势,对Ni3Fe合金反相畴界的结构和界面能进行模拟研究,结果表明保守型反相畴界的能量低于非保守型反相畴界对的能量,前者的弛豫现象也没有后者明显;FeNi型反相畴界出现收缩;NiNi型反相畴界出现扩张.二者相伴出现,形成平行非保守对,这为实验上发现的平行非保守反相畴界对提供了间接证据.  相似文献   

14.
1INTRODUCTION Titaniummonoxidepossessesbeautifulgolden color[15].Furthermore,theresultsdeterminedby aspectrachronometerindicatedthatthecolorofsingle phaseTiOx,withproperoxygenindex,was moresimilartothecolorof24KgoldthanTiNand Cubasedimitatedgold.BecauseTiOhasgoodsta bilityanddiscoloration resistingpropertiesinair,rainandroomatmosphere,properacid resistant andalkali resistantabilitiesandrelativelyhigh hardness,soTiOisanewkindofmaterialswithabrightfutureformanufacturingimitatedgold.But …  相似文献   

15.
Glass forming ability of Zr-and Fe-based alloys at quenching from melts   总被引:1,自引:0,他引:1  
0 INTRODUCTIONSincethefirstsynthesisofanamorphousphaseintheAu Sisystembyarapidsolidificationtechniquein196 0 [1,2 ] ,agreatnumberofamorphousalloyshavebeenproducedforthelastthreedecades.ItiswellknownthatFe ,Co andNi basedamorphousalloysfoundbeforere quiredhighco…  相似文献   

16.
In order to improve the hydriding and dehydriding kinetics of the Mg2Ni-type alloys, Ni in the alloy is substituted by element Co. The nanocrystalline and amorphous Mg2Ni-type Mg2Ni1−x Co x (x=0, 0.1, 0.2, 0.3, 0.4) alloys were synthesized by melt-spinning technique. The structures of the as-cast and spun alloys were studied with an X-ray diffractometer (XRD) and a high resolution transmission electronic microscope (HRTEM). An investigation on the thermal stability of the as-spun alloys was carried out with a differential scanning calorimeter (DSC). The hydrogen absorption and desorption kinetics of the alloys were measured with an automatically controlled Sieverts apparatus. The results demonstrate that the substitution of Co for Ni does not alter the major phase of Mg2Ni but results in the formation of secondary phase MgCo2. No amorphous phase is detected in the as-spun Co-free alloy, but a certain amount of amorphous phase is clearly found in the as-spun Co-containing alloys. The substitution of Co for Ni exerts a slight influence on the hydriding kinetics of the as-spun alloy. However, it dramatically enhances the dehydriding kinetics of the as-cast and spun alloys. As Co content (x) increases from 0 to 0.4, the hydrogen desorption capacity increases from 0.19% to 1.39% (mass fraction) in 20 min for the as-cast alloy, and from 0.89% to 2.18% (mass fraction) for the as-spun alloy (30 m/s).  相似文献   

17.
通过线性DSC实验研究了轧制对Zr60Al15Ni25大块非晶合金晶化动力学的影响。实验结果表明,Zr60Al15Ni25非晶合金在轧制塑性变形过程中,随着变形量的增加,热稳定性降低。Zr60Al15Ni25块体非晶合金轧制后原子组态的变化主要影响晶化的形核阶段,变形量较低时(20%)合金原子组态向无序方向发展,导致晶化速率变慢,晶化变得比较困难。随着轧制的进一步增加,合金原子的无序性降低,晶化速率又逐渐提高,从而使其在随后加热过程中的晶化变得比较容易。  相似文献   

18.
1 Structure and composition of thermal barrier coatings The thermal barrier coatings (TBCs), having superior properties of heat resistance, corrosion resistance, wear resistances and low heat conductivity, are mainly used in the aeronautic turbines with large thrust force-weight ratio. In TBCs ceramics is covered on the metal matrix in the form of coatings to withstand high service temperature [1]. Today most of the TBCs have the dou-ble-layer- structure of alloy matrix + the bonding laye…  相似文献   

19.
通过快速凝固法制备Ti50.2Ni29.8Cu20合金薄带,并利用XRD(X射线衍射仪)、DSC(差示扫描量热仪)、TEM(透射电子显微镜)等手段研究退火温度和退火时间对Ti50.2Ni29.8Cu20合金薄带马氏体相变的影响.结果表明,退火处理后Ti50.2Ni29.8Cu20合金薄带的室温相主要是B19马氏体和少量...  相似文献   

20.
On the basis of the alloying theory of bonding assistant coat (BAC), taking into account of the interaction of alloy elements, the regressive equation, which relates the wetting ability of bonding assistant coat with the contents of Mn, Ni, Si, Sn, and B, was es- tablished by using quadratic regression orthogonal design of five factors. The influence of elements and their interaction on the wetting ability was analyzed. The ranges of alloy elements were optimized. The melting point of bonding assistant coat was measured by using differential thermal analysis. The results show that the interactions of Ni and Mn, Ni, and Sn can increase the wetting ability obviously and the melting point of bonding assistant coat has been decreased.  相似文献   

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