共查询到19条相似文献,搜索用时 62 毫秒
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研究了镁合金AZ91D-0.3%Be-Sr的阻燃性及Sr对合金显微组织和力学性能的影响,结果表明,在镁合金AZ91D中加入0.3%Be。显著提高了阻燃性,使试验合金可在无覆盖和保护的条件下直接暴露在大气中熔炼。加入少量Sr可使镁合金AZ91D-0.3%Be-Sr的组织得到细化,力学性能显著提高。X射线衍射分析表明,阻燃机理是在合金液表面形成致密的MgO-BeO复合保护膜,阻止了镁合金的进一步氧化燃烧。 相似文献
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Y对AZ61镁合金阻燃及微观组织和力学性能的影响 总被引:1,自引:1,他引:0
研究了元素Y对AZ61镁合金起燃点及铸态微观组织和力学性能的影响.结果表明,将适量Y加入AZ61镁合金能提高其起燃点,改善组织,细化晶粒.由于显微组织的改善,合金的室温力学性能得到明显提高.当Y含量为1.5%时,合金的起燃点由556 ℃提高到595 ℃,提高了39 ℃,阻燃效果最好.当Y含量为1.0%时,合金的起燃点由556 ℃提高到592 ℃,提高了36 ℃,阻燃效果较好;同时合金晶粒的细化效果最好,其力学性能也最佳,抗拉强度较AZ61镁合金提高了13.5%,伸长率较AZ61镁合金提高了17.8%. 相似文献
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研究了Ni-45Ti合金化和机械振动对ZA27合金显微组织、力学性能和热疲劳性能的影响,利用光镜对合金显微组织和热疲劳裂纹进行了观察。结果表明:加入适量的Ni-45Ti合金化和机械振动的合金,组织得到显著细化,力学性能与热疲劳性能得到明显提高;随着Ni-45Ti加入量的增加,抗拉强度和伸长率呈现先提高再降低的变化规律;在Ni-45Ti为0.6%时的合金具有最优的综合力学性能。研究还发现,0.6%Ni-45Ti合金化和机械振动的合金裂纹长度最短,并具有最好的热疲劳性能。 相似文献
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研究了Sn对AZ91镁合金显微组织和力学性能的影响。结果表明:合金中加入Sn形成的颗粒相MgzSn使合金组织晶粒变细,使晶间组织β相由连续网状变得不连续,并且提高了合金的力学性能。当Sn含量为1%时,合金的力学性能最佳,抗拉强度为187MPa,硬度为76HV,与未加Sn的aZ91相比,分别提高了30%和31%。 相似文献
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对封闭式镁合金熔炼及浇注集成系统进行了较为详细的介绍,并对传统工艺和新工艺制备的镁合金进行了微观分析和力学性能测试.结果表明,新工艺集熔炼、处理、浇注于一体,整个过程封闭、连续进行,熔炼的AZ31-0.6Nd 合金与传统工艺相比,Nd的吸收率提高了125.7%,显微组织得到细化,析出相数量增加,并有Mg12Nd化合物形成,且含Nd和不含Nd的AZ31合金的力学性能均明显提高. 相似文献
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WenChun-sheng RongYong-hua T.Y.Hsu XuZu-yao 《材料热处理学报》2004,25(5):161-164
A nanostructured surface layer can be formed in Ni metal treated by surface mechanical attrition (SMA). The microstructure was investigated by using optical microscope, X-ray diffractometer and transmission electron microscope,respectively. Mechanical property measurements indicate that the yield strength of the surface layer raises significantly while the tensile strength somewhat changes and the elongation percentage reduces severely compared with that of the inside layer. Meanwhile, yield-drop-like phenomenon occurs in the surface layer after SMA treatment. In order to compare the mechanical behavior of nanostructured materials with two phases, Fe-30Ni nanostructured alloy was also investigated. 相似文献
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机械镀锌快速活化工艺 总被引:19,自引:3,他引:16
机械镀锌工艺中起关键作用的是锌粉团在工件上的吸附、强化和稳定这一过程可以提高沉积速度。采用表面活性剂复合成活化剂,使得被镀表面与锌粉团之间始终保持吸附电位差,形成金属粉快速而稳定地沉积;采用非锡类金属盐和无机酸式氨盐复合成沉积剂,利用金属离子还原的引忸作用和氨基的络合作用使镀层细化,结合强度提高 。 相似文献
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In Shup Ahn Kwang-Chul Jung Sang Shik Kim Yoo Young Kim 《Metals and Materials International》1999,5(6):619-624
Al-10%Nb alloy powders were fabricated by mechanical alloying and their mechanical behavior and microstructure were investigated
by means of tensile testing, differential scanning calorimetry, X-ray diffraction and electron microscopy. An intermetallic
compound of Al3Nb was partially formed in the mechanically alloyed powders. The grain size was 50 run after mechanical alloying for 20 hours,
and increased to 500 nm after hot extrusion at 400°C. However the 20 size of the intermetallic compounds of precipitated Al3Nb in an Al matrix, did not vary with hot extrusion. The density of the consolidated Al-Nb alloy was over 97% relatively with
hot extrusion. Both the tensile strength and elongation decreased at the elevated temperature. As the temperature increased,
the dimples in the fracture surface were large and of coalescent shape, and the fracture was caused by the precipitated phases
of Al3Nb. 相似文献
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In this paper, dense bulk nanocrystalline (nc) nickel electrodeposits with various grain sizes were produced by using high frequency pulse current and strong electrolyte flushing. The effects of the grain sizes on the mechanical properties were discussed for room and a medium temperature. It was found that the properties of the deposited nickel such as microhardness, corrosion resistance and yield stress (at room temperature and 473 K) were improved substantially with the decrease in the grain size. A deviation of yield stress from the Hall-Petch relationship for nc nickel was observed when the grain sizes were decreased to less than 70 nm at room temperature. A low yield stress value of nc nickel was obtained at a temperature of 673 K as a result of its thermodynamic instability. 相似文献
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讨论了在力学性能不确定度评定中的几个问题。着重指出,如果所用的测量器具符合文件要求,则其不确定度可以按规定的文件评定。 相似文献
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研究了钨基合金中钨的含量与其显微组织、断裂方式及力学性能之间的关系。结果表明,随着钨含量的增加,钨邻接值增加.合金的抗拉强度增加;当钨含量到达一定值后,强度可达最高,再增加钨含量,强度则急剧下降。 相似文献
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Pt—Pd—Rh合金的高温力学性能 总被引:5,自引:2,他引:5
在Pt-4Pd-35Rh合金中将Pd含量增至15wt%时,研究了Pd及少量Ce、Ru对合金在1000℃以下高温力学性能的影响。实验结果表明在低温下Pd有一定的强化作用,但降低了合金的抗蠕变性能,而在合金中分别添加Ce(<01wt%)、Ru(<05wt%)后,合金的高温力学性能得以改善并优于Pt-4Pd-35Rh合金,且Ce对合金的强化作用优于Ru。 相似文献