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本文首先讨论了Co对Ni-Cr-Co基合金的强化作用。指出,合金中加入钴主要是由于降低了合金堆垛层错能,(0%Co;20%Co合金分别为72.7;36.3erg/cm~2)拉宽了扩展位错的宽度,使位错攀移和交叉滑移在晶体中更难进行而强化了合金。其次讨论了W、Mo对合金的强化作用。指出,W、Mo综合强化不如以W单独强化的较果更好。因为,即使含有少量Mo也易析出尺寸较大的含Mo的μ相,使合金的室温塑性大幅度下降。W可提高合金的蠕变激活能(W含量为16%;18%;20%蠕变激活能分别为78.11;92.33;120.44kcal/mol,降低合金的稳态蠕变速率。W也可以降低合金的堆垛层错能。 相似文献
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Mo对TiC基金属陶瓷组织和性能的影响 总被引:1,自引:1,他引:0
通过对8种成分各异的试样进行强度、硬度测试以及全相和扫描电镜分析,研究Mo、WC、Co及Cr3C2对TiC基金属陶瓷组织结构和力学性能的影响。结果表明:加入Mo,可提高液相对固相的润湿性,促进烧结致密化和细化晶粒,有利于合金强度和硬度的提高;但将在硬质相外缘形成一种比较脆的环形相(Ti,Mo,W)C组织,对合金强度带来不利影响。WC、Cr3C2和Co的加入可一定程度地降低环形相脆性的影响,改善TiC基金属陶瓷的力学性能。 相似文献
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高铬铸铁堆焊层因其较高的耐磨性而广泛应用于各种大型工业设备的内部衬板,研究发现Mo系碳化物可为初生碳化物的生成提供形核点从而细化组织,但Mo元素除了提供形核点外是否对组织存在别的作用仍尚待研究。为了研究Mo含量对高铬铸铁堆焊层组织与性能的影响,设计了一种含Mo超高碳高铬堆焊耐磨板,利用XRD、SEM分析了Mo元素对堆焊层组织、相组成以及磨损后堆焊层表面和纵截面的影响,利用EDS分析了元素在各相中的分配情况,并进一步利用硬度和干砂磨料磨损试验,研究了Mo合金化对高铬高碳堆焊层硬度和耐磨性的影响。结果表明,Fe-Cr-Mo-C合金堆焊层组织主要由γ相、M7C3(M=Fe、Cr)组成。随着Mo含量的提高,堆焊层内初生碳化物含量降低,奥氏体含量增加,单个初生碳化物尺寸先减小后增大;初生碳化物硬度增加,堆焊层宏观硬度先增加后降低;磨损后初生碳化物截断裂纹减少,剥落逐渐减少,其中30Mo试样出现了共晶碳化物的剥落。加入0.13%Mo后磨损失重减少了13.6%,加入0.30%Mo后磨损失重增加了20.0%。这是因为Mo原子的加入会提高初生碳化物的硬度,但是... 相似文献
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以新型高强铝锂合金(Al-Cu-Li)为研究对象,合金经过520 ℃固溶淬火后分别在165 ℃时效6 h和165 ℃时效18 h,然后采用高分辨电子显微镜观察Al-Cu-Li铝锂合金显微组织中δ相和T1相的形貌和晶格像,研究了主要强化相T1相的形核机制。结果表明:单胞T1相为五层密排六方堆垛结构,T1相的化学堆垛次序为CBABC。观察发现T1相既可以单独在基体形核生长,也可以依附在原有的T1相上形核以台阶方式生长。细小的球形析出相δ相为有序结构相,并且与基体共格。 相似文献
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采用燃烧合成法成功制备了CoCr Mo合金。燃烧合成的合金是由钴的两种固溶体组成,分别为密排六方的ε-CoCr Mo相和面心立方的γ-CoCr Mo相;渣相主要为Al2O3;合金的微观结构为铸态树枝晶,并且存在枝晶偏析现象,枝晶上富钴,枝晶间富钼,铬分布比较均匀;此外,燃烧合成过程中可能产生马氏体相变使γ-Co相转变为ε-Co相,并且在马氏体片中出现了带状亚结构。 相似文献
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对不同Mo含量(5%、10%、15%和20%,质量分数)的二元Ti-Mo合金的显微组织和机械性能进行了研究。结果表明:当Mo含量为5%时,合金由单一的等轴α相组成;Mo含量为10%时,等轴α晶粒内部有针状析出物;当Mo含量为15%、20%时,合金由单一的等轴声β组成。Mo含量为10%,合金的综合性能最好:硬度为4510MPa,压缩强度为1636MPa,压缩率为22.5%,弹性模量为29.8GPa。Mo含量的增加有利于合金组织的细化,塑性的提高。Ti-Mo合金是一种有发展前景的口腔修复用钛合金。 相似文献
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GH3625合金中碳的质量分数约为0.05%,由于含有较高的铌、钼和铬元素,合金中会形成 MC型、M6C型和M23C6型碳化物,在冶炼凝固过程中由于选分结晶的原因,易产生碳化物偏聚问题。因为碳化物回溶温度偏高,在其可锻温度区间内很难消除,所以会导致合金棒材中存在碳化物条带状聚集的问题,对其服役性能影响较大。利用Thermal-calc热力学软件计算分析了GH3625合金平衡析出相及一次碳化物的析出规律,利用金相显微镜、扫描电镜等研究了镁对GH3625合金一次碳化物形貌、尺寸及分布的影响。结果表明,GH3625合金的基体为单一的奥氏体相,MC型碳化物作为一种高温析出相,直接从液相析出,其富含铌元素,其次还有少量的钛、钼等元素。而随着凝固温度的降低,铌质量分数逐渐升高;未加镁时,GH3625合金在二次枝晶间析出了大量长条状的一次碳化物,其平均直径和面积较大;加入质量分数为0.014%的镁后,镁通过改变碳化物相与基体相的比界面能关系,不仅有效地改善了合金枝晶间和晶界碳化物的分布及形貌,还减小了一次碳化物的尺寸;当镁质量分数增加到0.037%时,一次碳化物分布更加均匀弥散,此时镁细化、球化碳化物的效果最好;同时,试验合金在水冷和空冷的条件下,由于冷却速率比炉冷时更大,一次碳化物析出尺寸也相对更细小。 相似文献
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Havva Kazdal Zeytin Hakan Yildirim Banu Berme Selim Duduolu Gürkan Kazdal Adem Deniz 《钢铁研究学报(英文版)》2011,18(11):31-39
Heat treatment methods were applied to white cast iron for improving the impact and wear resistance. Additionally, chemical composition optimization was made. Furthermore, the effect of boron addition on such applications was investigated. Samples were investigated by using optical and electron microscope methods. Hardness, wear and impact tests were conducted. The results showed that the secondary carbides in the standard alloy were iron-enriched, needle-like carbides M3C when the boron-added alloy contained Fe23(C,B)6 type, globular secondary carbides. It was concluded that heat treatment B provided higher wear and hardness properties, compared to the standard heat treatment. Optimum mechanical properties were obtained by lower destabilisation temperatures and increasing temperature reduced the wear resistance and hardness. 相似文献
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CoCrCuFeNiMox (x values in molar ratio, x?=?0, 0.2, 0.4 and 0.8) high-entropy alloys were prepared by mechanical alloying and spark plasma sintering method. The effects of Mo addition on microstructure and mechanical properties were investigated. The X-ray diffraction (XRD) result showed that the addition of Mo into CoCrCuFeNi high-entropy alloy (HEA) changed the original phase constitution from FCC to FCC?+?σ?+?μ and the peak intensity of (1 1 1) shifted to the left and decreased steadily. The field emission scanning electron microscope confirmed that the Cu-rich second FCC phase disappeared and the σ phase with a tetragonal structure expanded as the Mo content was increased. Additionally, a high density of dimple-like features were seen in CoCrCuFeNi HEA while typical quasi-cleavage facets could be observed from the fracture surfaces of the HEAs with the addition of Mo. The Mo0.8 alloy showed a good wear resistant and appropriate strength with fracture strain 22.70%, fraction coefficient 0.65, hardness 530?HV and compressive strength 1448?MPa.Special theme block on high entropy alloys, guest edited by Paula Alvaredo Olmos, Universidad Carlos III de Madrid, Spain, and Sheng Guo, Chalmers University, Gothenburg, Sweden. 相似文献
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采用TiAl合金靶材,在TC4钛合金基材表面以不同磁控溅射工艺沉积制备了TiAlN涂层。利用扫描电子显微镜(SEM)、能谱仪(EDS)、X射线衍射仪(XRD)分别分析了不同工艺制备的TiAlN涂层的表面形貌、表面成分及相结构,并对TiAlN涂层的耐蚀性、耐磨性等进行了研究。结果表明,采用磁控溅射工艺可在TC4钛合金表面制备出表面相对平整且结构致密的TiAlN涂层;沉积了TiAlN涂层的TC4钛合金试样的表面性能得到了提高,其磨损失重量和TC4钛合金基材相比降低了80%,耐盐雾腐蚀性能达到了保护级9级。 相似文献
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Inconel 690合金TT处理后的析出相 总被引:1,自引:0,他引:1
用扫描电子显微镜、透射电子显微镜和相分析研究了3种不同钛含量的Inconel 690合金经不同固溶温度+715 ℃×15 h,TT处理后的析出相。结果表明:合金经TT处理后,均有M23C6析出,并含有一定量的Ti(C,N);钛含量为110%的合金中有γ′相析出,γ′相在晶内弥散分布;M23C6大多在晶界上析出,而且在孪晶界和晶内位错线处也均有析出,M23C6与界面一侧基体保持立方 立方的平行位向关系;钛含量增加,析出的M23C6尺寸变小,间距增大,晶界附近的铬含量明显提高,有利于改善合金的耐腐蚀性能。 相似文献
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LIMing-xi SISong-hua HEYi-zhu SUNGuo-xiong 《钢铁研究学报(英文版)》2004,11(4):59-62
The SiCp (20%) reinforced cobalt-based alloy composite coatings deposited by lasercladding on IF steel were introduced. The microstructure across the whole section of such coat-ings was examined using optical microscope, scanning electron microscope (SEM) and X-raydiffractometer (XRD), and the wear resistance of the coatings was measured by MM-200 typewear testing machine. The results show that the SiCp is completely dissolved during laser clad-ding and the primary phase in the coatings is r-Co. The other phases, such as SizW, CoWSi,Cr3Si and CoSi2, are formed by carbon, silicon reacting with other elements existing in themelting pool. There are various crystallization morphologies in different zones, such as planarcrystallization at the interface, followed by cellular and dendrite crystallization from interface tothe surface. The direction of solidification changes from one direction perpendicular to interfaceto multi-directions at the central and upper regions of the clad. The wear resistance of the cladis improved by adding SiCp. 相似文献
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Chao-ping JIANG Ya-zhe XING Feng-ying ZHANG Jian-min HAO Xu-ding SONG 《钢铁研究学报(英文版)》2014,21(10):969-974
Fe-based and Fe/Mo composite amorphous coatings were deposited on the surface of plain carbon steel substrates by atmospheric plasma spraying (APS). With increasing the Mo alloy content, the microstructure of the coatings revealed more dense structure. The porosities of composite coating were all less than those of Fe-based coat- ing due to Mo alloy self-bonding performance. The ML10 friction and wear tester was employed to investigate the wear behaviors of the coatings under dry sliding conditions. It was found that the mass loss of the resultant coatings decreased with increasing Mo-based powders into the feedstock. This was attributed to the reduction of the delamina- tions resulting from improved intersplat bond with Mo addition. 相似文献
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利用激光熔覆技术在Q235钢基体表面分别制备出添加不同质量分数Y2O3的AlCoCrFeNi高熵合金涂层。采用X射线衍射仪、扫描电子显微镜、显微硬度计和摩擦磨损试验机对AlCoCrFeNi高熵合金涂层的微观组织、硬度及摩擦磨损性能进行了分析。结果表明:AlCoCrFeNi高熵合金涂层由面心立方结构(FCC)和体心立方结构(BCC)两相构成;随着Y2O3质量分数的提高,其体心立方结构相体积分数增加,而面心立方结构相的体积分数变化呈相反趋势。AlCoCrFeNi高熵合金涂层组织由等轴晶构成,加入Y2O3后,促进了熔池流动,使气孔逐渐消失,致密性提高,晶粒明显细化。添加质量分数5%Y2O3的涂层组织呈树枝晶状,形成弥散分布的YAl2和Y2O3相;涂层的显微硬度可达HV 350,约为AlCoCrFeNi高熵合金涂层硬度的2倍,强化效果明显。Y2O3的添加有利于促进涂层中体心立方相的形成和YAl2相的析出,能有效提高高熵合金涂层的硬度及耐磨性能。 相似文献
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本文通过高速电弧喷涂技术在低碳钢基体上制备Fe基涂层, 采用光学显微镜(OM)、 扫描电子显微镜(SEM)、
白光干涉仪表征涂层的微观结构以及磨痕形貌, 通过维氏硬度计、 摩擦磨损试验机检测涂层的机械性能。 研究结
果显示涂层呈典型的片层状结构, 涂层较为致密, 孔隙率为 1.75±0.22%。 硬质相元素的添加提高了涂层的微观
硬度, 涂层的硬度大约是基体的四倍。 同时, 涂层的磨损量相对基体来说降低了 78.61%, 对磨球切削基体表面
形成较深的犁沟, 而涂层因硬度较大, 形成的沟槽较浅, 并且涂层表层出现脆裂、 剥落现象, 产生大量的磨粒,
使得基体与涂层的磨损机制由粘着磨损向磨料磨损转变 相似文献