WC-Co硬质合金γ相相变

通过Ｘ射线衍射相分析和应力分析研究了ＷＣ－Ｃｏ硬质合金γ相（钴基Ｃｏ－Ｗ－Ｃ固溶体）的相转变。ＷＣ－Ｃｏ硬质合金在烧结后至富温的冷却过程中γ相以扩散型机制为主进行ｆｃｃ→ｈｃｐ相变,其非扩散型的Ｍｓ转变点在室温以上并接近室温,室温下上烧结态合金中ｈｃｐ含量很少。在Ｍｓ点以下,凡引起合金中ＷＣ相与γ相间内应力变化（加强或松弛）的工艺因素均能导致合金γ相ｈｃｐγ相比例的增加。     

液相烧结钼基合金粘结相的研究

研究了粘结相的成分Ｎｉ和Ｃｕ的变化对液相烧结Ｍｏ－Ｗ－Ｎｉ－Ｃｕ合金性能的影响。结果发现，随镍铜量或镍铜比的增加，烧结温度下降，合金的晶粒球化，细化。当镍铜比一定，合金的抗拉强度随镍铜量的增加先是急剧上升，然后缓慢下降，当镍铜量一定，抗拉强度随镍铜比的增加亦有上述关系。当镍铜比为２．４，镍铜量为６％，烧结温度不低于１３８０℃时，液相烧结钼基合金几乎无孔隙，抗拉强度可达１１００ＭＰａ，晶粒呈鹅卵石状     

添加羰基铁粉提高铁基合金烧结密度的研究

在Ｆｅ－Ｎｉ－Ｃｕ－Ｍｏ－Ｃ系合金中添加羰基铁粉，改善了粉料的压制性能和粉坯的烧结性能。以钢模成形、一次烧结工艺制造的合金，密度达７．５２ｇ／ｃｍ＾３，相对密度９５．２％，提高了制品的力学性能。     

钨钼活化烧结机理

主要介绍了添加少量Ｎｉ－Ｃｏ时钨，钼的低温烧结特性，对比了纯钨，Ｗ－Ｃｏ，Ｗ－Ｎｉ，Ｗ－Ｎｉ－Ｃｏ，纯钼，Ｍｏ－Ｃｏ，Ｍｏ－Ｎｉ，Ｍｏ－Ｎｉ－Ｃｏ烧结体系，测算了这些体系的烧结活化能，研究了其低温烧结机理，发现Ｎｉ－Ｃｏ对钨，钼的烧结具有最好的活化效果，说明镍与钴的共同加入对钨，钼的烧结具有协同活化作用。     

添加Cu对WC—13?／Co／Ni硬质合金性能与组织的影响

讨论了加入少量Ｃｕ对ＷＣ－１３％Ｆｅ／Ｃｏ／Ｎｉ硬质合金性能和组织的影响。叙述了在扫描电镜和透射电镜下，对该合金进行的金相观察和微观组织研究结果。结果表明，Ｃｕ有细化和球化ＷＣ晶粒的作用，当加Ｃｕ量为０．８％左右时，合金的性能最佳，其抗弯强度比未加Ｃｕ的合金高６７０Ｎ／ｍｍ＾２，可达到２３７０Ｎ／ｍｍ＾２。此外，合金在烧结后的缓冷过程中发生马氏体相变，其马氏体与γ相符合Ｋ－Ｓ取向关系。     

烧结温度对WC－TiC－Co两相合金的影响

对不同温度烧结的ＷＣ－ＴｉＣ－Ｃｏ两相合金的组织结构进行了全面的观察和分析，并对不同温度烧结的刀片进行了切削试验。结果表明：由饱和的ＴｉＣ－ＷＣ（质量比为３０：７０）固溶体与Ｃｏ粉制成的两相合金，在各种烧结温度下都会出现游离的ＷＣ相，且其相对量随着烧结温度的升高而减少；合金中碳化物的晶粒尺寸随着烧结温度的升高而增大；当烧结温度为１４８０℃时，合金的切削寿命具有最大值。     

含稀土和过渡元素Keggin结构混配型杂多酸盐的热解性质研究

本文研究了通式为Ｋ１０Ｈ３〔Ｌｎ（ＳｉＭｏ９Ｗ２Ｏ３９）２〕·ｘＨ２Ｏ（简记为Ｌｎ（ＳｉＭｏ９Ｗ２）２，Ｌｎ＝Ｌａ、Ｃｅ、Ｐｒ、Ｎｄ、Ｓｍ、Ｅｕ、Ｇｄ、Ｄｙ、Ｔｂ、Ｙｂ，以下相同），Ｋ１０Ｈ３〔Ｌｎ（ＳｉＭｏ６Ｗ５Ｏ３９）２〕·ｘＨ２Ｏ（简记为Ｌｎ（ＳｉＭｏ６Ｗ５）２）、Ｋ１０Ｈ３〔Ｌｎ（ＳｉＭｏ２Ｗ９Ｏ３９）２〕·ｘＨ２Ｏ（简记为Ｌｎ（ＳｉＭｏ２Ｗ９）２）和Ｍｍ＋Ｈ４－ｍＳｉＭｏ１０Ｗ２Ｏ４０·ｘＨ２Ｏ（简记为ＭＳｉＭｏ１０Ｗ２，Ｍ＝Ｃｒ、Ｍｎ、Ｆｅ、Ｃｏ、Ｎｉ、Ｃｕ、Ｚｎ、Ｃｄ）４个系列３８种化合物的热解性质，确定它们的分解温度分别为：Ｌｎ（ＳｉＭｏ９Ｗ２）２，２５０～３００℃；Ｌｎ（ＳｉＭｏ６Ｗ５）２，３００～３５０℃；Ｌｎ（ＳｉＭｏ２Ｗ９）２，３５０～４００℃；ＭＳｉＭｏ１０Ｗ２，３８０～４２０℃，详细研究了稀土和过渡元素取代钼对化合物热解性质的影响。     

少量Al对WC—13?／Co／Ni硬质合金性能的组织的影响

以ＷＣ－１３％Ｆｅ／Ｃｏ／Ｎｉ合金作为基体合金，添加少量Ａｌ以研究其对ＷＣ－１３％Ｆｅ／Ｃｏ／Ｎｉ硬质合金的性能和组织的影响，结果发现，Ａｌ可以细化合金中的ＷＣ晶粒，并在提高合金硬度的同时，使其抗弯强度提高１００～２００ＭＰａ，金相研究表明，添加Ａｌ的ＷＣ－１３％Ｆｅ／Ｃｏ／Ｎｉ合金中的粘结相主要是γ相和板条马氏体，局部有α＋（Ｆｅ，Ｍｅ）３Ｃ的片层状组织存在。     

少量A1对WC－13％Fe／Co／Ni硬质合金性能和组织的影响

以ＷＣ－１３％Ｆｅ／Ｃｏ／Ｎｉ合金作为基体合金，添加少量Ａ１以研究其对ＷＣ－１３％Ｆｅ／Ｃｏ／Ｎｉ硬质合金的性能和组织的影响。结果发现：Ａ１可以细化合金中的ＷＣ晶粒，并在提高合金硬度的同时，使其抗弯强度提高１００～２００ＭＰａ。金相研究表明，添加Ａ１的ＷＣ－１３％Ｆｅ／Ｃｏ／Ｎｉ合金中的粘结相主要是γ相和板条马氏体，局部有α＋（Ｆ，Ｍｅ）＿３Ｃ的片层状组织存在。     

添加Cu对WC－13％Fe／Co／Ni硬质合金性能与组织的影响

讨论了加入少量Ｃｕ对ＷＣ－１３％Ｆｅ／Ｃｏ／Ｎｉ硬质合金性能和组织的影响。叙述了在扫描电镜和透射电镜下，对该合金进行的金相观察和微观组织研究结果。结果表明，Ｃｕ有细化和球化ＷＣ晶粒的作用，当加Ｃｕ量为０．８％左右时，合金的性能最佳，其抗弯强度比未加Ｃｕ的合金高６７０Ｎ／ｍｍ２，可达到２３７０Ｎ／ｍｍ２。此外，合金在烧结后的缓冷过程中发生马氏体相变，其马氏体与γ相符合Ｋ—Ｓ取向关系。     

Segregation of molybdenum atoms to the liquid-solid interfaces in liquid phase sintering of W-8 pct Mo-7 pct Ni-3 pct Fe

Partitioning of elements during sintering of W-8 pct Mo-7 pct Ni-3 pct Fe alloy was investigated with respect to various isothermal holding times, ranging from 5 to 240 minutes, at a sintering temperature of 1500 °C. It was found that the precipitation of W and Mo atoms from the liquid phase onto the W-Mo grains was competitive in nature, with W atoms showing a greater tendency to precipitate. Due to this fact, Mo atoms gradually segregated to the interface between W-Mo grains and the liquid phase. The accumulation of Mo atoms near the interfaces thus changed the interfacial properties and, consequently, reduced the rate of interfacial reaction (solution and precipitation), which was responsible for the transition of the controlling mechanism of grain growth from diffusion of W atoms in the liquid phase to the interfacial reaction.     

Homogeneous steel infiltration

The direct manufacture of metal parts by rapid prototyping (RP) often involves using a metal powder. Densification of the powder can be done either by sintering or infiltration. Infiltration avoids the shrinkage and distortion that typically accompanies sintering. However, in steels, the use of copper or bronze infiltrants limits the usefulness of parts because of the nonhomogeneous structure and properties. In this work, a conventional tool steel alloy has been made via homogeneous steel infiltration (HSI), a gated infiltration process that uses as the infiltrant a steel alloy with a lower melting point than the base powder. The infiltrant liquid uses carbon or silicon as a melting point depressant (MPD). Freeze-off of the steel infiltrant is avoided by infiltrating at a temperature at which some liquid is stable at chemical equilibrium. Examples of successful infiltrations using D2 tool steel as a target composition are shown. Mechanical properties (hardness and impact strength) following various heat treatments of the infiltrated D2 are compared with conventional wrought D2 tool steel and found to be very similar. The HSI is believed to be suitable to a wide variety of tool steels and stainless steels. Further, the process is applicable to the postprocessing of any suitable steel skeleton made by RP, as well as other powder metallurgy processes, such as metal injection molding.     

铜基高通量换热管内多孔层的制备及性能研究

烧结型高通量换热管是通过在普通换热管内表面烧结一定厚度的多孔金属层达到强化沸腾传热的效果,多孔层的烧结温度对基管性能不能有损伤,同时要求多孔层本身孔隙连通,与基管结合较好,且耐蚀性与基管相当。本文设计了一种适用于铁白铜基管（BFe10-1-1）的管内多孔层烧结合金粉末Cu-10% Ni-20% Zn-2% Sn（质量分数）,该粉末成分耐蚀性优于基管。烧结实验结果表明,该合金粉末在940℃下烧结时对基管性能无损伤,烧结后与基管结合良好,同时粉末多孔层内部孔隙均匀联通;进一步的应用实验也证明,该多孔层合金粉末具有非常好的传热效果。     

Effect of alloying method on sintering and physico-mechanical properties of Al-A.4% Cu-0.5% Mg powder alloy

Conclusions The method of alloying with copper and magnesium has a strong effect on compacting in sintering and on the physicomechanical characteristics of Al-4.4% Cu-0.5% Mg alloy.The alloy based on Al-0.5% Mg master alloy is characterized by the highest density but its sintering requires higher temperatures (615–635°C) and long holding times. This alloy produced in the optimum conditions is characterized by high physicomechanical properties in the sintered state but by low efficiency of heat treatment. The optimum physicomechanical properties were recorded for the alloy containing the elementary powders of copper and magnesium which was sintered at 595°C for 45 min.Translated from Poroshkovaya Metallurgiya, No. 10(310), pp. 37–41, October, 1988.     

多次烧结对钨铜合金组织与性能的影响

对熔渗法制备的钨铜合金(CuW80)分别进行了3、6、9次烧结。采用金相显微镜、扫描电子显微镜、X射线衍射仪、压汞仪等表征手段,研究了烧结次数对CuW80合金组织和性能的影响。结果表明:随着烧结次数的增加,CuW80合金中钨颗粒直径逐渐增大并连接,铜相分布更加均匀,多次烧结未见新相生成;经过3次烧结后,试样孔隙率由最初的0.5185%变为2.0516%,孔径增加主要集中在0.5~3μm范围内,但9次烧结后试样的孔隙率大大降低;合金硬度由烧结前的HB 204变化至烧结后的HB 188;试样电导率由25.06 mS/m降低至21.92 mS/m;合金密度较烧结前降低了1.2%。     

铁基粉末冶金配流盘渗铜质量影响因素

介绍了烧结熔渗铜技术生产高密度、高强度铁基粉末冶金配流盘的基本工艺方法．重点分析了骨架、熔渗剂、烧结熔渗时间等影响铁基粉末冶金配流盘渗铜质量的主要因素。对提高同类铁基粉末冶金机械零件渗铜质量具有重要借鉴意义。     

铜钨/铬青铜整体触头的真空烧结熔渗

采用真空烧结熔渗方法制备了CuW80/CuCr0.5自力型整体触头,测试了CuW合金的理化性能以及CuW/CuCr结合面的抗拉强度,对比了不同工艺制备的CuW80/CuCr0.5触头抗拉强度值。结果表明,真空烧结CuW80/CuCr0.5触头中的CuW80合金具有良好的性能,其致密度可达98.9%以上,CuW/CuCr结合面的抗拉强度最高,可以达到395 MPa以上,能够满足高压及超高压开关的技术要求。真空烧结的CuW80/CuCr0.5触头组织均匀、致密,结合面洁净,无气孔、杂质,Cu相之间连通并均匀的包覆在W颗粒周围,这是导致其结合强度高的主要原因。     

Design and fabrication of W-Mo-Ti-TiAl-Al system functionally graded material

To obtain a kind of functionally graded material (FGM) with a density gradient, the W-Mo-Ti-TiAl-Al system graded material was designed, and the powder metallurgy method was chosen for its fabrication. The sintering of W, W-Mo, and Mo-Ti alloys at low temperature was studied, and then the approximately wholly dense W-Mo-Ti-TiAl system FGM was achieved by one-step sintering at 1473 K for 1 hour under a pressure of 30 MPa. It was found that through sintering at 1473 K, mainly the mechanical mixtures of W and Mo were formed in W-Mo alloys. In Mo-Ti alloys, the newly designed Fe-Al sintering aids not only have an important effect on the densification of the alloys, but also contribute to the formation of the (Mo, Ti) solid solution. However, the solid-solution reaction that occurred in Mo-Ti alloys was still insufficient. During the sintering of Ti + TiAl, the chemical reaction of Ti + TiAl → AlTi₂ was induced within the sintered body. The W-Mo-Ti-TiAl-Al system FGM was finally fabricated by joining of the TiAl side of the sintered W-Mo-Ti-TiAl system FGM to metal Al with an Al-based brazing filler metal, and its density changed quasi-continuously within the large range from 17.15 to 2.70 g/cm³.     

Fe-Cu-Pb-C系含油轴承的研制

研究了Fe-Cu-Pb-C系合金烧结温度范围和铜的加入量对合金性能的影响。铅是固体润滑剂,可提高Fe-C系合金的减摩性能,虽然铅的加入使合金的强度有所下降,但通过加入铜能有效地抑制强度的降低。     

Fe－Cu－Pb－C系含油轴承的研制

研究了Ｆｅ－Ｃｕ－Ｐｂ－Ｃ系合金烧结温度范围和铜的加入量对合金性能的影响。铅是固体润滑剂，可提高Ｆｅ－Ｃ系合金的减摩性能，虽然铅的加入使合金的强度有所下降，但通过加入铜能有效地抑制强度的降低。