共查询到18条相似文献,搜索用时 46 毫秒
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Al—P中间合金变质剂在Al—Si活塞合金中的应用 总被引:2,自引:1,他引:1
在生产条件下比较了用Al-P中间合金与磷盐变质剂处理共晶和过共晶Al-Si合金的工艺特点、变质效果、力学性能和综合成本等,结果表明:使用Al-P中间合金操作方便,变质效果好、且稳定、力学性能也有不同程度的提高,而且该中间合金无渣、无污染,其使用可以实现生产过程的“零时间”变质处理,节约能源,提高生产效率,提高合金的实收率,降低产品的综合成本,有着良好的应用前景。 相似文献
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本文研究了自制新型Al-P中间合金对共晶及过共晶Al-Si的变质作用。发现该Al-P中间合金对共晶及过共晶Al-Si合金都具有优良的变质效果。同时还发现,当铝合金熔体中存在TiC颗粒时,Al-P中间合金对两类Al-Si合金的变质效果会增强。当Al-24Si合金中TiC含量为0.03%时,初晶Si的平均尺寸由原来的47μm降为41μm,最大尺寸由原来的75μm降为55μm;加入Al-P中间合金和TiC颗粒后50分钟,就可以出现变质效果,时间再延长,变质效果也不会有更大的提高,当Al-12Si合金中TiC含量为0.03%时,初晶Si的平均尺寸幅度原来的50μm降为30μm,Al-P中间合金变质剂在铝合金活塞中有较好的应用。 相似文献
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本文在研究开发红梅-1号多功能磷复合变质剂、红梅-2号磷酸盐块状变质剂和红梅-3号特种合金磷变质剂的基础上,紧密联系活塞生产的实际,对Al-Si合金采用磷变质的各项工艺参数进行了研究探讨,重点对应用红梅-3号的工艺参数进行了研究探讨;同时,对磷变质相关的几个理论性的问题作了阐述,并对ZLl08和ZLl09合金成分的工艺配比提出了我们的建设性意见,希望对从事活塞生产已经和准备采用磷变质的厂家有一定指导意义。 相似文献
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作者研制的锶盐长效复合变质剂用于ZL104合金,对共晶硅的变质效果良好,提高了合金的力学性能。变质处理时,没有潜伏期,有效时间达7小时以上,对生产环境无污染。 相似文献
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《International Journal of Hydrogen Energy》2023,48(78):30354-30364
In this work, self-standing binary porous PdM (M = Ni, Fe and Co) foam-like nanostructures are rationally designed by a rapid and one-step aqueous-solution method, including ice co-reduction of metal precursors using sodium borohydride. Amongst the tested PdM nanostructures, the PdNi nanostructures delivered a superior alkaline ethanol oxidation reaction (EOR) activity and stability than those of PdFe, PdCo, and commercial Pd/C catalysts. The EOR mass activity of PdNi (4.81 A/mgPd) was 1.32, 1.51, and 24.05-folds of PdFe (3.62 A/mgPd), PdCo (3.19 A/mgPd) and Pd/C (0.2 A/mgPd), respectively based on equal Pd mass loading. This was attributed to the lower synergetic effect of PdNi, which enhanced activation/dissociation of H2O to afford OH- species required for fast EOR kinetics; meanwhile, porous foam-like nanostructure improved electron mobility and increased accessible active sites. This study reveals that low synergism in porous PdM nanocrystals is beneficial for augmenting the EOR activity, which may allow the design of other binary Pd-based alloys for various electrocatalytic reactions. 相似文献
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Chunsheng Wan Zemin Shi Min Huang Jinhua Pan Ruizhi Luo Dalin Li Lilong Jiang 《International Journal of Hydrogen Energy》2021,46(5):3833-3846
Cobalt-, iron-, and copper-substituted nickel-aluminum hydrotalcite-like compounds (Ni2.7Co0.3Al, Ni2.7Fe0.3Al, Ni2.7Cu0.3Al HTlcs) have been synthesized and used as precursors to prepare Ni–Co, Ni–Fe, and Ni–Cu alloy catalysts for methane decomposition. The catalysts before and after reaction were characterized with various techniques including XRD, H2-TPR, HAADF-STEM-EDX, SEM, TEM, and Raman. The characterization results indicate that upon calcination HTlcs are transformed into a mixed oxide solid solution, where cobalt, copper, and iron ions are incorporated into the nickel oxide, and the reduction treatment leads to composition-uniform alloy particles. In methane decomposition at 600 °C, alloying Ni with Co, Fe, and especially Cu is found to enhance the catalytic life and carbon yield. The order of activity is Ni2.7Cu0.3Al >> Ni2.7Fe0.3Al > Ni2.7Co0.3Al > Ni3Al in terms of carbon yield, highlighting that Ni–Cu alloying is the most effective. Besides, Ni–Cu alloying remarkably changes the carbon morphology, giving carbon nanofibers as the main product. TEM and STEM measurements suggest that Ni–Cu alloy particles are readily aggregated into big particles (>60 nm) under the reaction conditions, which may be responsible for the significant effect of Ni–Cu alloying. 相似文献
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To evaluate the effect of the alloy phase characteristics on the ethanol oxidation activity, carbon supported (PtSnPd)alloy/SnO2 catalysts were prepared and their electrocatalytic activity compared with that of carbon supported (PtSn)alloy/SnO2. Pt-Sn-Pd/C samples in the atomic ratio (1:1:0.3) and (1:1:1) were characterized by energy dispersive X-ray (EDX) analysis, X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM). XRD analysis shows the presence of fcc Pt reflexions, shifted to lower angles, and SnO2 reflexions. By comparison with the XRD patterns of carbon supported Pt-Sn (1:1) and Pt-Pd (3:1) samples, prepared by the same method, the formation of ternary PtSnPd alloys is postulated. The crystallite size of the ternary catalysts is smaller than that of both binary Pt-Sn/C (1:1) and Pt-Pd/C (3:1) catalysts. Chronoamperometry experiments and tests in direct ethanol fuel cells of the as-prepared catalysts shows that the activity for ethanol oxidation of (PtSn)alloy/SnO2 is higher than that of (PtSnPd)alloy/SnO2. This result, obtained with the same Pt/SnO2 atomic ratio in all the samples, indicates the critical role of the alloy phase characteristics of these catalysts on their activity for ethanol oxidation. 相似文献
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Two types of Pt- and Ni-based alloy catalysts were synthesized and comparatively tested for hydrogen generation from aqueous borazane (ammonia- borane, BH3NH3) solution. The experimental results demonstrated that hydrogen release rates from some of the Pt alloys such as PtRu and PtAu are nearly 9 times higher than those from pure Pt surface, and similarly, most of the Ni alloy catalysts exhibit greatly enhanced catalytic activities than pure Ni catalyst. Particularly, hydrogen release from NiAg-catalyzed BH3NH3 hydrolysis can complete quickly at room temperature showing a stable hydrogen yield at H2/BH3NH3ratio=2.9 (molar ratio), corresponding to 8.7 wt % hydrogen release. Since the Ni alloy catalysts are less costly and highly efficient, it is feasible to use the Ni alloy catalysts for practical hydrogen generation in portable applications. 相似文献