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Au与Au合金材料近年的发展与进步 总被引:4,自引:1,他引:4
总结与评述了自本世纪以来Au与Au合金材料在科学技术与应用方面取得的一些新进展,其内容包括Au与Au合金冶金学研究、Au与Au合金新材料和新的加工制备技术3个方面.在冶金学方面,简单介绍了某些新的Au合金相图研究和Au合金向多元合金化和微合金化方向的发展.新的Au与Au合金材料研究包含电气工业用新材料、电子工业用新材料、饰品与牙科新材料及先进复合材料和涂层材料等.Au材料的加工技术也获得了新的发展.最后,总结和评述了Au与Au合金材料应用的发展趋势. 相似文献
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John Banhart 《Gold bulletin》2008,41(3):251-256
The possibilities to manufacture gold-based foams are explored. Gold powder and various powdered alloying elements are mixed
with a small volume fraction of a gas-releasing blowing agent. The blend is compacted to a dense precursor, which is then
melted in a further step in order to trigger foam formation. We find that gold-silicon alloys containing 2–3 wt.% of silicon
or around 8 wt.% of germanium can be foamed using TiH2 or ZrH2 as a blowing agent. Foams with about 85% porosity are obtained. 相似文献
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The age-hardening behavior and the mechanism of an experimental low gold content casting Ag-Pd alloy were studied by means of hardness test, XRD, SEM and EPMA, The results show that the hardness of specimens isothermal-aged at 400 oC after solution treated at 900 oC for 30 min increases unidirectionally from 1540 MPa to 3160 MPa with the prolongation of time. However, the hardness of the specimens isothermal-aged at 600 oC after solution treated at 900 oC for 30 min increases quickly and reaches the maximun 2870 MPa at 2 min aging time. Then the hardness decreases unidirectionally and remains at 1600-1700 MPa from 10 to 50 min aging time. Obvious precipitation takes place in the specimens isothermal-aged at 400 and 600 oC revealed by XRD. By SEM and EPMA, the precipitation particles can be seen in the specimens aged at 600 oC for 2 min after solution treated at 900 oC for 30 min. However, the time-FWMH curve shows that the increase of hardness after isothermal-aging is closely related with coherency stain from phase transformation. It is hard to define whether the phase transformation at 400 oC makes a contribution to the change of hardness 相似文献
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在淬火基体成分计算的基础上,根据某一淬火温度下的奥氏体基体的化学成分,Cr W Mo V合金钢淬火硬度可以近似计算为HRC=α(1+β)/(0.00915α+0.00527),其中α为基体中含碳量的平方根,β为合金元素对马氏体强化的修正因子。上述淬火硬度计算公式隐含着洛氏硬度测定和马氏体强化机理的对应关系,对其它钢种也适用。Cr W Mo V高合金钢在高温回火时会出现二次硬化特征,二次硬化的最高回火硬度既与各类型碳化物沉淀的热力学和动力学有关,也与残余奥氏体分解过程有关。依据奥氏体化温度下基体成分,提出基体成分配比碳公式为Cp=0.011W+0.02Mo+0.057Cr+0.19V,二次硬化的回火硬度的计算公式为Hc=a(1+b)/(00127a+000267),其中a为基体碳饱和度,b为碳化物沉淀量的修正因子。 相似文献
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海水泵阀用新型铸造铜合金的研制 总被引:3,自引:0,他引:3
研制了一种海水泵阀用新型铸造铜合金,该合金综合力学性能优良:δb≥550MPa,δ0.2≥280MPa,δ5≥18%;耐海水腐蚀性能优异,在7m/s的天然海水冲刷下,腐蚀率低于0.042mm/a,在3.5m/s的含砂海水冲刷下,腐蚀率为0.144mm/a;与目前推广使用的海水管系材料B1O的腐蚀电位相差较小,电偶腐蚀率为0.0092mm/a,能有效抑制海水管系的电流腐蚀,提高海水泵阀的使用寿命。与国内海水泵阀常用的铜合金相比,该合金具有较高的拉伸强度和屈强比,能承受较高的压力,在深海工程等领域也有广泛的应用前景。 相似文献
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Hot Deformation Behavior and Hardness of a CoCrFeMnNi High-Entropy Alloy with High Content of Carbon
Yi-Tao Wang Jian-Bo Li Yun-Chang Xin Xian-Hua Chen Muhammad Rashad Bin Liu Yong Liu 《金属学报(英文版)》2019,32(8):932-943
A CoCrFeMnNi high-entropy alloy with a high content of carbon was synthesized, and its hot deformation behavior was studied at the temperatures 800–1000 ℃ at the strain rates ranging from 0.001 to 0.1 s~(-1).As-prepared alloy is a face-centered cubic-structured solid solution, with a large amount of carbides residing at grain boundaries.True stress–strain curves were employed to develop the constitutive equation of apparent activation energy.The apparent activation energy( Q) was found to be 423 kJ mol~(-1), indicating a dynamic flow softening behavior.The size of dynamic recrystallized(DRXed) grains increases with increasing the temperature or decreasing the strain rate.A processing map was sketched on the basis of the flow stress.The temperature range of 900–1000 ℃ and 10~(-3)–10~(-2.6) s~(-1) strain rate were found to be the optimum hot-forging parameter.With increasing temperature or decreasing strain rate, the volume fraction of fine carbides(≤ 1 μm) increases.A lot of coarse carbides can be found in the matrix after deformation at 800 ℃, which leads to a high hardness value of 345 HV.The carbides after deformation at 1000 ℃ are mainly nano-sized M_7C_3 and M_(23)C_6, which can promote the nucleation of DRX. 相似文献
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熔制的Ni-Cu-P合金显微组织由Ni-Cu,Cu-Ni两种固溶体枝晶和弥散其中的Ni3P组成。随着磷含量的增加,Ni-Cu-P合金的硬度显著提高。热处理对Ni-Cu-P合金的显微组织和硬度无显著影响。 相似文献
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设计试验方案,制备金相试样,将试样进行热处理,用金相显微镜观察记录显微组织,并选定洛氏硬度作为硬度测试参数,对热处理前后的金相组织进行观察、硬度的测定。 相似文献
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FeCoNiCuMox多主元合金的组织与硬度研究 总被引:1,自引:0,他引:1
采用X射线衍射、扫描电镜和硬度测试等方法,研究了Mo含量对FeCoNiCuMox多主元合金微观组织和硬度的影响.结果表明,合金由简单的FCC相和BCC相组成,随Mo含量的增多,FCC相含量减少,BCC相含量增多,共晶组织的含量增加,硬度逐渐增大,当x=1时,FeCoNiCuMo合金的硬度值为478 HV. 相似文献
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R. Wilson 《金属精饰学会汇刊》2013,91(1):42-49
Brief comparison has been made between the alkaline cyanide and acid citrate gold plating baths. Operating conditions of a proprietary acid bath and their effect on cathode efficiency have been investigated. The low gold and nickel metal content generally adopted in these baths and the marked effect of slight variation in these metals on the characteristics of the deposit and trouble-free running of the process make regular analytical control important, as this affects economy of process and quality of product. Brief mention has been made of the application of atomic absorption spectrophotometry as a convenient means of analytical control. Plating distribution can be greatly improved by careful consideration of anode configuration and cathode jig design. The most suitable anode material was found to be gold strip, or as an alternative, platinized expanded titanium mesh. In the proprietary acid bath under consideration, carbon or stainless steel anodes were found to be unsuitable. 相似文献
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YG30硬质合金与因瓦合金TIG焊接头的组织与硬度的分析研究 总被引:3,自引:3,他引:0
本文选用不同厚度的Ni-Fe、Ni-Fe-C-Mn-Nb因瓦合金,与YG30在不加填充材料、对接条件下直接进行TIG焊接试验,运用光学显微镜、扫描电镜、显微硬度仪等对焊接接头的显微组织和硬度进行研究分析。结果表明,Ni-Fe因瓦合金与YG30连接,在YG30/因瓦合金焊接接头界面区硬质合金侧形成η-碳化物;Ni-Fe-C-Mn-Nb因瓦合金与YG30连接,在界面区没有η-碳化物形成。不同厚度、不同工艺参数的焊接接头中,厚度为2mm、电流为135A和厚度为4mm、电流为145A的两种焊接接头组织均匀,界面冶金结合良好,硬度分布过渡平缓。 相似文献
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介绍了活塞、活塞环、轴瓦涂层硬度的试样制备过程及注意要点,强调正确制备试样是测量涂层硬度的基础。分析了维氏硬度测量误差的来源,指出试验载荷选择遵循的原则,并分别就轴瓦涂层硬度、活塞环涂层硬度、活塞涂层硬度的测量方法进行了讨论,说明正确选择涂层硬度的测量方法至关重要。 相似文献