共查询到19条相似文献,搜索用时 140 毫秒
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采用累积轧制(ARB)技术在室温下对1060工业纯铝进行轧制试验,用光学显微镜、透射电镜、拉伸试验机研究分析了变形前及不同道次后材料的微观组织和力学性能。结果表明:材料经轧制后,获得小于1μm的细晶粒,在ARB 7道次后得到了平均晶粒尺寸为520 nm的超细晶组织;随着ARB道次的增加,材料的抗拉强度在ARB 4道次后达到最大值197 MPa,之后略有降低;硬度值上升,在ARB 4道次后变化平缓;伸长率在ARB前3道次过程中从23%下降到9%,随着ARB道次的增加,伸长率回升,在ARB 7道次后为16%。 相似文献
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在不同轧制速度(512,768,1 024 mm·s-1)下对均匀化退火态ZK60镁合金板进行4道次热轧,分别采用单向(4道次方向相同)和交叉(1,3道次方向与2,4道次方向垂直)2种轧制方式,研究了轧制方式和速度对镁合金板组织和力学性能的影响。结果表明:与单向轧制相比,交叉轧制镁合金板的组织均匀性和综合力学性能较好;随着轧制速度的增加,动态再结晶晶粒尺寸先减小后增大,抗拉强度先升后降,断后伸长率增大。在交叉轧制和768 mm·s-1的轧制速度下,ZK60镁合金板可获得良好的组织和力学性能,此时镁合金板已基本发生完全再结晶,晶粒细小均匀,抗拉强度为322.4 MPa,断后伸长率为15.7%。 相似文献
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采用不同异速比(1.2~1.8)和轧制路径对MB1镁合金板材进行异步轧制,对轧制得到合金板材的显微组织和力学性能进行了研究。结果表明:开始随着异速比(<1.6)的增大,MB1镁合金板材的显微组织逐渐细化,孪晶数量不断减少,抗拉强度和伸长率增大;当异速比为1.6时,合金的晶粒最均匀细小,平均尺寸约为20μm,且几乎没有孪晶,抗拉强度为235 MPa,伸长率达到23%;再进一步增大异速比,合金的力学性能又有所下降;按不同路径进行轧制,合金的晶粒逐步细化、均匀,孪晶依次减少,板材的伸长率按路径A,B,C,D的顺序逐步升高,强度逐步降低。 相似文献
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P. Asadi M. K. Besharati Givi N. Parvin A. Araei M. Taherishargh S. Tutunchilar 《The International Journal of Advanced Manufacturing Technology》2012,63(9-12):987-997
This paper deals with an experimental investigation focused on the effects of water cooling treatment, friction stir processing pass number, and tool rotational direction on the microstructure and mechanical properties of friction stir processed AZ91 magnesium alloy. Specimens were produced using different combinations of process parameters. Parallel to increasing the amount of oxide particles in the processed area, water cooling was found to reduce the final grain size and enhance their hardness and strength. Changing the rotational direction in each pass reduces the grain size severely (from 150 to ~4?μm) and increases the hardness (from 63 to 98?HV) and strength (from ~130 to ~250?MPa). However, no significant difference was found in wear resistance of the specimens produced with different process parameters. 相似文献
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用XRD、SEM、EDS和显微硬度仪等研究了固溶、时效处理对真空精炼的含0.164 8%(质量分数)镧AZ91镁合金显微组织和力学性能的影响。结果表明:加入微量镧后的AZ91镁合金在410℃×24h空冷固溶+170℃×30h空冷时效后,第二类β相大量析出,且呈不连续层片状沿晶界两侧分布;时效态含镧AZ91镁合金的抗拉强度、屈服强度、伸长率和显微硬度分别比铸态不含镧AZ91合金的提高了41.84%,65.08%,35.65%和47.62%;其原因是微量镧改变了热处理中铝原子的扩散状态,有效控制了第一、二类β-Mg17Al12相析出时的形态与分布。 相似文献
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L. LITYSKA-DOBRZYSKA J. DUTKIEWICZ W. MAZIARZ & A. KANCIRUK† 《Journal of microscopy》2009,236(2):119-122
Atomized 6061 aluminium alloy powders with and without the addition of 2 wt% Zr were milled for 80 h in a planetary ball mill and hot pressed in vacuum. The milled powders showed microhardness of about 170 HV, which increased after hot pressing up to 260 HV and up to 280 HV for powders without and with the Zr additions, respectively. Compression tests showed the high yield stress of 300 MPa obtained for the hot-pressed sample produced from the initial powders compared with ultimate compression strength of above 800 MPa for that of the milled sample and slightly higher for that with Zr additions. The effect of hot pressing on the structure of powders was investigated using a conventional analytical and high-resolution electron microscopy and high angle annular dark-field scanning transmission electron microscopy combined with energy dispersive X-ray microanalysis. The samples of initial powders hot pressed in vacuum showed a cell structure with particles of the Mg2 Si and AlFeSi phases in intercell areas. In the milled and hot-pressed sample, the homogeneous structure of small grains of size below 200 nm was observed. The AlFeSi and Mg2 Si particles with size 20–100 nm were uniformly distributed as well as the Zr rich particles in the Zr containing alloy. The Zr-rich particles containing up to 80 at% Zr were identified as a metastable fcc cubic phase with lattice parameter a = 0.48 nm. 相似文献
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测试了不同增强颗粒质量分数的纳米CeO2/Zn-4.5Al-RE复合材料的力学性能,测定了柱形试样熔化前后的高度变化率,讨论了复合材料的表观粘度,并研究了纳米CeO2含量对两者的影响规律.结果表明:CeO2的加入提高了基体的力学性能,当其含量为3%时,复合材料的维氏硬度、弹性模量和抗拉强度分别达到96.7 HV,17.1 GPa和176.5 MPa,较基体分别提高了41.2%,34.6%和34.2%,而伸长率则降低了4.6%;随着CeO2含量的增加,复合材料的高度变化率△H/H0大大降低,粘度急剧增大. 相似文献
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文中介绍了某雷达MB8镁合金冷板的双轴肩搅拌摩擦焊接试验。双轴肩搅拌摩擦焊接技术对夹具设计以及应用环境的要求较常规搅拌摩擦焊接低。本试验中搅拌头转速设计为1000~1600 r/min,焊接速度设计为100~160 mm/min。通过测量冷板焊接接头处的拉伸强度和硬度,分析了焊接工艺参数对接头力学性能影响的机制。试验结果表明,MB8镁合金冷板双轴肩搅拌摩擦焊接接头处没有出现未焊透、气孔和夹杂等镁合金熔焊常见的缺陷,接头处的拉伸强度为199~211 MPa,平均拉伸强度达到母材强度的91%,接头处布氏硬度为30~39 HBS ,相比母材略有下降。试验结果说明双轴肩搅拌摩擦焊接技术非常适合用于冷板以及其他结构件的焊接。 相似文献