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1.
在Co-Ni-Al系合金的基础上用Cu部分代替Al,制备4种不同成分的合金,研究热处理对Co38Ni34Al28-xCux显微组织和显微硬度的影响。结果表明,Co38Ni34Al27.5Cu0.5合金经1350℃×2 h加热、冰水冷却至室温处理后,β基体内出现马氏体,而Co38Ni34Al27Cu1则在1350℃×2 h和1300℃×4 h处理时都出现马氏体。随铜含量的增加和铝含量的减少,合金β相晶粒变小,γ相晶粒和含量变大。Co38Ni34Al27.5Cu0.5的显微硬度随温度升高而升高,在β相晶粒内出现马氏体时,Co38Ni34Al27Cu1合金的显微硬度骤降。  相似文献   

2.
快速凝固Ni48Mn33Ga19合金的加热相变组织和结构的研究   总被引:1,自引:0,他引:1  
采用铜模吸铸式快速凝固法制备了非化学计量成分的Ni48Mn33Ga19合金,研究和比较了经常规冷却和吸铸式快速冷却工艺热处理后合金相变点以及组织和结构的变化规律。结果表明,加热相变过程均为两阶段相变过程;快速凝固工艺可使铸后热处理试样的相变温度接近室温;极高的冷却速率提高了组织均匀性;Ni48Mn33Ga19合金组织经热处理后由奥氏体转变成10层马氏体。  相似文献   

3.
在Co38Ni34Al28合金体系中添加 Sn,研究Sn含量及不同的热处理温度(1373 K,1473 K,1573 K)下,保温2h对Co38Ni34Al28-xSnx(x=1,2,3)合金显微组织和硬度的影响。结果表明,添加适量的Sn使合金中γ相组织减少;在1573K保温2h后,在室温下获得部分马氏体组织;当Sn 替代 2%Al 时,其显微组织中马氏体组织的比例较高。随着Sn含量的增多和热处理温度的升高,合金的硬度也随着增大。另外,合金马氏体的逆相变温度在Sn含量为1%和2%时升高,在Sn含量为3%时反而降低。  相似文献   

4.
研究了高温固溶和时效热处理对12Ni无钴马氏体时效钢微观组织和性能的影响。结果表明:在原始固溶态试样中存在粒状和长粒状析出相,经能谱分析为Fe(Mo,Ti)或Fe2Ti型金属间化合物,消耗了大量的强化元素Mo,导致合金时效处理后强度不足(1100MPa);高温固溶处理后消除了粗大析出相,获得单一的板条马氏体组织;进一步改进时效热处理工艺,合金组织呈现弥散分布的纳米尺度的Ni3Mo、Ni3Ti强化相,使合金强度显著提高,达到1225MPa。  相似文献   

5.
95W-5(Ni/Fe/Co)合金的低温显微组织和力学性能   总被引:4,自引:0,他引:4  
分析了95W-5(Ni/Fe/Co)合金的粉末冶金工艺特点及低温显微组织与力学性能,给出了力学性能与温度的关系曲线.通过对合金拉伸试样断口的扫描电镜分析,揭示了该合金低温力学性能与组织变化的微观本质.结果表明:95W-5(Ni/Fe/Co)合金室温下具有较高的强度及一定的塑性;该合金低温脆化的主要原因是由于屈服强度随温度的降低而增加,钨颗粒过早解理及粘结相变形极小引起的;95W-5(Ni/Fe/Co)合金的冷脆性转变温度在-50℃左右,此时脆性断裂以钨颗粒的自身解理为主.  相似文献   

6.
马氏体不锈钢铸件焊接接头组织和性能分析   总被引:1,自引:1,他引:0  
运用小孔法测量马氏体不锈钢铸件ZG1Cr12Ni3Mo2Co2VN焊接接头回火前、后的残余应力;采用SEM和金相相结合的方法,观察了该焊件的组织和断口形貌;测量焊接接头金属的显微硬度.试验结果表明,焊件接头未回火室温基体金属的显微组织为脆硬的马氏体,且存在着较大焊接残余应力;回火后,焊件接头的显微组织为回火索氏体,改善了钢的塑性及韧性,提高了合金的综合力学性能.  相似文献   

7.
采用电弧熔炼法制备Co38Ni34Al27Mn1磁控形状记忆合金,并对合金进行热处理.采用金相显微镜、X射线衍射仪及振动样品磁强计等研究热处理工艺对Co38Ni34Al27Mn1合金显微组织、相结构及磁性能的影响.研究结果表明:1573 K加热冰水淬火后得到β相和γ相,而1623、1673 K加热冰水淬火后合金中可观察到板条状马氏体,且β相、γ相和马氏体相共存.随着热处理温度的提高,合金晶粒长大,γ相体积分数减小,马氏体含量增加,饱和磁化强度从42.51 emu·g-1增加到45.43 emu·g-1,矫顽力从48 Oe减小到30 Oe;在1673 K淬火,随加热保温时间的增加合金晶粒变大,饱和磁化强度从44.31 emu·g-1增加到47.29 emu·g-1.  相似文献   

8.
用冷坩埚磁悬浮熔炼方法制备铸态La0.7Mg0.3(Ni0.81Co0.15Al0.04)3.4贮氢电极合金,并在1173 K温度下热处理8 h得到热处理态合金,采用XRD、FESEM及EDS研究相结构、显微组织及相成分.Rietveld法全谱拟合分析表明,铸态及热处理态合金为多相结构,主相为Ce2Ni7型六方相,还包括CaCu5型六方相、PuNi3型菱方相、MgCu2型立方相及BCr型正交相.热处理后Ce2Ni7型主相含量从63.6%(质量分数)增加到70.1%,热处理还使各组成相的晶胞体积均有所增加.铸态合金的显微组织为板条状,热处理后板条状组织消失.FESEM结合EDS分析表明,热处理使铸态合金中的Ni相消失且出现富Mg相,同时使主要贮氢相间Ni元素和Mg元素的浓度差减小.  相似文献   

9.
用激冷甩带法制备了Ti-46Ni合金薄带,用扫描电子显微镜、X射线衍射仪、示差扫描热分析仪和弯曲试验研究了合金薄带的组织特征、相变行为和形状记忆效应。结果表明,铸态及400~600℃退火态Ti-46Ni合金薄带的显微组织形态呈树枝状,晶粒细小,由B19?马氏体和B2母相组成;在冷却、加热过程中,该合金薄带发生一阶段马氏体相变;铸态和退火态Ti-46Ni合金薄带均具有良好的形状记忆效应。  相似文献   

10.
退火时间对Ti-49.8Ni形状记忆合金组织和形变行为的影响   总被引:2,自引:0,他引:2  
用光学显微镜、X射线衍射仪及拉伸试验机研究退火态Ti-49.8Ni形状记忆合金的显微组织和形变行为.结果表明,冷加工和400 ℃退火态Ti-49.8Ni合金的组织呈纤维态,退火时间对合金组织影响不大.Ti-49.8Ni合金室温组成相主要为马氏体,随退火时间延长,400 ℃退火态合金弹簧的马氏体再取向应力先降低后升高,600 ℃退火态则升高.随形变温度升高,不同退火态合金弹簧的马氏体再取向应力升高,弹簧刚度增加.适合该合金变形加工的退火工艺为600 ℃×1 h.  相似文献   

11.
In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.  相似文献   

12.
After nearly two years' tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry (SRIF), located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.  相似文献   

13.
Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.  相似文献   

14.
The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.  相似文献   

15.
The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process could be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets would solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results.  相似文献   

16.
On the basis of the single-particle framework, a new theory on inclusion growth in metallurgical melts is developed to study the kinetics of inclusion growth on account of reaction and collision. The studies show that the early growth of inclusion depends on reaction growth and Brawnian motion collision, and where the former is decisive, the late growth depends on turbulence collision and Stokes' collision, and where the former is dominant; collision growth is very quick during the smelting process, lessened in the refining process, but nearly negligible in the continuous casting process.  相似文献   

17.
An approach based on film buckling under simple uniaxial tensile testing was utilized in this paper to quantitatively estimate the interfacial energy of the nanostructured multilayer films(NMFs) adherent to flexible substrates. The interfacial energies of polyimide-supported NMFs are determined to be *5.0 J/m2 for Cu/Cr, *4.1 J/m2 for Cu/Ta,*2.8 J/m2 for Cu/Mo, *1.1 J/m2 for Cu/Nb, and *1.2 J/m2 for Cu/Zr NMFs. Furthermore, a linear relationship between the adhesion energy and the interfacial shear strength is clearly demonstrated for the Cu-based NMFs, which is highly indicative of the applicability and reliability of the modified models.  相似文献   

18.
A 17 vol% SiCp/Al–Mg–Si–Cu composite plate with a thickness of 3 mm was successfully friction stir welded(FSWed) at a very high welding speed of 2000 mm/min for the first time. Microstructural observation indicated that the coarsening of the precipitates was greatly inhibited in the heat-affected zone of the FSW joint at high welding speed, due to the significantly reduced peak temperature and duration at high temperature. Therefore, prominent enhancement of the hardness was achieved at the lowest hardness zone of the FSW joint at this high welding speed, which was similar to that of the nugget zone. Furthermore, the ultimate tensile strength of the joint was as high as 369 MPa, which was much higher than that obtained at low welding speed of 100 mm/min(298 MPa). This study provides an effective method to weld aluminum matrix composite with superior quality and high welding efficiency.  相似文献   

19.
吴玉梅  熊晓云  靳蓉  孙敬民  杨林  罗晓星 《金属学报》2005,10(10):1100-1103
目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。  相似文献   

20.
On the basis of energy and shape method for the determination of the valence bond (VB) structures of crystal, the valence bond structure of titanium is redetermined at room temperature and calculated in the whole temperature range of 0-1943K. The outer shell electronic distribution of Ti is e_c~(2.9907) · (s_c~(0.4980) d_c~(2.4927)) ef1.0093 in crystal. The temperature dependences of the VB structures of hcp and bcc phases are the same. The VB structures of hcp and bcc phases monotonically increase or decrease with the increase in temperature, but show discontinuous changes at the phase-transformation temperature 1155K.  相似文献   

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