WC—8（Fe／Ni／Co）R硬质合金的研究

用Ｆｅ、Ｎｉ部分取代ＷＣ－８Ｃｏ合金（牌号ＹＧ８）中的粘结剂Ｃｏ,再添加微量稀土Ｒ制得ＷＣ－８（Ｆｅ／Ｎｉ／Ｃｏ）Ｒ硬质合金,测试了其物理机械性能,研究了粘结剂各种成份比例及烧结温度对硬质合金的影响。结果表明：ＷＣ－８（Ｆｅ／Ｎｉ／Ｃｏ）Ｒ硬质合金的性能可以达到ＹＧ８的性能标准。利用扫描电镜（ＳＥＭ）及Ｘ射线衍射（ＸＲＤ）对其作了显微结构分析,同时探讨了影响ＷＣ－８（Ｆｅ／Ｎｉ／Ｃｏ）Ｒ合金性能的     

过渡金属添加剂对W—Cu液相烧结的影响

为了加快Ｗ－Ｃｕ复合材料的液相烧结过程，添加Ｃｏ，Ｆｅ和Ｎｉ到铜中，钨和这些元素添加剂的烧结行为随添加剂的变化而发生很大的变化，尽管致密化的速度由于这些元素的适当加入而可能大大地提高，为了形成一连续而加入必要的过量钴添加剂时，会使烧结速率不断下降。而随着加了铁的数量增加却没有发现其烧结速率降低，增加Ｎｉ添加剂烧结速度连续提高。液态铜对钨表面的润湿性的差别是因为添加剂对Ｗ－Ｃｕ复合材料的液相烧结的影     

Ti—6Al—4V合金微动磨损的表面防护

分析对比了Ｔｉ－６Ａｌ－４Ｖ合金经喷丸后抛光、火焰喷涂Ｃｕ涂层、等离子喷涂锡青铜、Ｃｕ－Ｎｉ－Ｉｎ和ＷＣ／Ｃｏ－Ｉ涂层、爆炸喷涂ＷＣ／Ｃｏ－Ⅱ、Ｎｉ－６０和化学镀镍磷镀层等处理后，在室温和５００℃下的抗微动磨损性能。结果表明：ＷＣ／Ｃｏ－Ｉ涂层有较好的综合防护效果。     

微量元素对Fe－36％Ni因瓦合金热膨胀系数的影响

微量元素对Ｆｅ－３６％Ｎｉ因瓦合金热膨胀系数的影响研究了分别添加不同微量元素Ｃ、Ｓｉ、Ｍｎ、Ｃｒ、Ｍｏ、Ｃｕ、Ｎｂ、Ｔｉ、Ｖ、Ａｌ、Ｗ和Ｂ等，对于Ｆｅ－３６％Ｎｉ因瓦合金在３０℃至１００℃和３００℃至４００℃温度范围内的热胀系数（α３０～１００℃和α...     

人体植入物用钴－铬合金

人体植入物用钴－铬合金美国卡彭特技术公司新近开发成功一种医疗用植入物用无磁钻一铬－钼合金，其典型的化学成分是：Ｃｏ－２６Ｃｒ—６Ｍｏ—１Ｓｉ－１Ｆｅ－１Ｍｎ－１Ｎｉ－０．５Ｗ－０．５Ｃｕ－０．１８Ｎ－０．０５Ｃ－０．０１５Ｐ－０．０１５Ｓ，该合金制品...     

W, Co, Ni对时效合金强度和韧性的影响

研究了Ｗ,Ｃｏ,Ｎｉ对时效合金强度和韧性的影响。结果表明：高Ｃｏ的ＦｅＷＣｏ合金有强的时效硬化能力,但其韧性较低。以Ｎｉ取代部分Ｃｏ之后,合金的韧性得到大的提高。ＦｅＷＣｏ合金的Ｃｏ量约２３％,Ｗ,Ｍｏ总量超过１８％时,硬度增加甚少,韧性损害较大,而ＦｅＷＣｏＮｉ的Ｃｏ当量达２３％,Ｗ,Ｍｏ总量达２４％时获得最佳的强度和韧性的配合。萃取化合物的Ｘ射线衍射（ＸＲＤ）分析表明,时效合金的主要金属间化合物是Ｆｅ３Ｗ２型,还有Ｆｅ７Ｗ６和Ｆｅ２Ｗ型化合物。淬火态、退火态萃取物的化学分析表明,时效合金中,Ｗ,Ｍｏ主要存在于化合物中,而Ｃｏ,Ｎｉ主要存在于固溶体中。时效硬化主要通过Ｗ,Ｍｏ金属间化合物的析出引起。而Ｃｏ,Ｎｉ主要通过影响析出相的数量、析出物形态及分布状态来影响时效硬化。     

应用d—电子合金设计理论发展新型抗热腐蚀单晶镍基高温合金 Ⅲ.性…

根据ｄ－电子合金理论研究了合金系统Ｎｉ－１６Ｃｒ－９Ａｌ－２Ｗ－１Ｍｏ－４Ｃｏ－Ｔｉ－Ｔａ－Ｎｂ（ａｔ．－％）的热腐蚀行为。选择了最佳成分范围内的４种成分进行单晶生长及性能评价。确定了性能匹配最佳的合金成分（ａｔ．－％）为：Ｎｉ－１６Ｃｒ－９Ａｌ－２Ｗ－１Ｍｏ－４Ｃｏ－３．１２５Ｔｉ－０．８７５Ｔａ。完成了整个合金设计过程。该合金抗热腐蚀能力达到或超过ＩＮ７３８ＬＣ，使用温度比ＩＮ７３８ＬＣ高７０     

WC—CoWC—NiWC钎焊涂层耐磨性研究

采用真空钎焊工艺,交硬质合金粉（ＷＣ－Ｃｏ,ＷＣ－Ｎｉ,ＷＣ）及钎焊合金（ＮｉＣｒＢＳｉ）焊到４２ＣｒＭｏ钢基体表面,研究了不同硬质全金粉对钎焊涂层抗磨料磨损性能的影响,初步分析了涂层磨损机制。     

热处理对Ni—Cr—W—Co—Fe—C合金组织结构的影响

研究了热处理工艺对粉末冶金Ｎｉ－Ｃｒ－Ｗ－Ｃｏ－Ｆｅ－Ｃ合金组织结构的影响。结果表明,烧结合金经９５０℃热处理可以获得最佳的组织和性能。热处理后粉末冶金合金的性能可超过真空熔炼的同类合金。     

磁体和磁性材料的技术经济分析

磁体和磁性材料的技术经济分析永磁体大致可分为烧结磁体和粘结磁体，这类材料包括各种合金、金属间化合物和，陶瓷，常用的有陶瓷硬磁性铁氧体、稀土合金（Ｎｄ－Ｆｅ－Ｂ和Ｓｉｎ－Ｃｏ）、Ａｉｎｉｃｏ（Ｆｅ－Ａｌ－Ｎｉ－Ｃｏ）、Ｃｕｎｉｆｅ（Ｃｕ－Ｎｉ－Ｆｅ）、...     

New insights into the accelerated sintering of tungsten with trace nickel addition

In Ni-doped W alloys, 1–4 wt% of Ni was often employed to accelerate densification in conventional sintering process but at the expense of restricted service temperatures because of formation of liquid phase. To break the dilemma, in this work 0.1 wt% Ni was alloyed into W matrix and achieved 98% relative density. The densification and grain growth behaviors of both pure and nickel doped tungsten compacts were investigated, in which a potential new accelerated sintering mechanism by solid-solution alloying was explored. First-principles calculations demonstrated the transition barrier for vacancies in W system was lowered by 34% upon Ni doping. This alloying process therefore was beneficial for lattice diffusion of tungsten that, in turn, improved the sintering performance and service abilities of tungsten-nickel alloy.     

注射成形高密度合金的变形控制

研究了注射成形高密度合金的变形行为和变形控制。实验表明,在液相烧结过程中,由于重力作用导致粘性流动,合金试样发生变形。对W含量较高的合金,采用二步烧结工艺可以有效地控制变形。在此工艺中,压坯首先在粘结相熔点以下温度烧结,形成W连通骨架,然后在高于粘结相熔点以上的温度下烧结较短时间以达到全致密;对于W含量较低的高密度合金,将原始混合粉末采用机械合金化,然后再进行固相烧结,可以得到性能很高的无变形的合金。     

Structure analysis of the constitutional phases in liquid phase sintered W–Mo–Ni–Fe heavy alloys

The crystal structures of constitutional phases in two different tungsten heavy alloys processed via different conditions were examined. The compositions of these two alloys were W–11.9Mo–17.0Ni–7.7Fe and W–29.6Mo–17.0Ni–7.7Fe (at.%), which were liquid phase sintered at 1500 °C for 5 or 240 min, and followed by either furnace-cooling or water-quenching. Increase in isothermal hold caused increased concentration of Mo but decreased concentration of W in the matrix phase, which did not affect the lattice parameter of the matrix phase to a significant extent. Quenching the specimen in water caused increase in the concentrations of both W and Mo in the matrix phase, and, consequently, increases in the lattice parameter of the matrix phase. A tungsten heavy alloy with a high alloying concentration of Mo was prone to induce the precipitation of an intermetallic phase during cooling, which was enhanced by increasing the isothermal hold at the liquid phase sintering temperature and decreasing the cooling rate. The structure of this intermetallic phase is analogous to that of MoNi, and can be designated as (W_xMo_1−x)(Fe_yNi_1−y). The composition of this intermetallic phase varied with the composition of the alloy and its cooling rate subsequent to sintering. For a furnace-cooling condition, the atomic ratio of W to Mo (x/1−x) in this intermetallic phase was about 0.47 times the atomic ratio of W to Mo of the original alloy composition. Such a proportional constant decreased to about 0.30 when the specimen was water-quenched.     

Effect of carbide additions on grain growth in TiC−Ni cermets

The growth of carbide particles in TiC-XC-2 vol.% Ni and TiC-XC-30 vol.% Ni alloys, where X=Zr, Cr, W, Ta and Mo, was fitted to an equation of the form d³-d_o ³=Kt. The grain growth behavior during liquid phase sintering at 1673K decreased markedly with the addition of Mo₂C or WC, changed little for TaC, and increased with the addition of ZrC or Cr₃C₂. The grain contiguity decreased with increasing Ni content in the TiC−Mo₂C−Ni alloy and was greater in the alloys with smaller growth rate constant. Consequently, the effect of carbide addition on the grain growth of 2 vol.% Ni alloys was found to be similar to that of 30 vol.% Ni alloys. The grain growth mechanism could be explained by the effect of contiguous carbide grain boundaries in restricting the overall grain growth, as well as the area of the solid/liquid interfaces in the alloy by the usual solution/reprecipitation model.     

纳米钨合金粉末的制备技术

钨合金包括W－Ni-Fe,W-Ni-Cu,W-Cu,WC-Co等钨基合金材料。钨合金材料将是21世纪出现的一种多功能高性能的多胜任的新型材料。有杉纳米粉末制备的亚微或微米钨合金块体材料具有非常优越的潜在物理力学性能,用作高性能结构件和高性能电子、微电子等功能材料方面都将具有很大的潜在优势,可以更好地满足高性能新型材料的要求。本文综合近几年来国内外纳米钨合金的研究状况,详细地介绍了有关纳米钨合金粉末的制备技术,预测了今后钨合金材料的研究方向。     

Microstructure and properties of liquid-phase sintered tungsten heavy alloys by using ultra-fine tungsten powders

The microstructure and properties of liquid-phase sintered 93W-4.9Ni-2.1Fe tungsten heavy alloys using ultra-fine tungsten powders (medium particle size of 700 nm) and original tungsten powders (medium particle size of 3um) were investigated respectively. Commercial tungsten powders (original tungsten powders) were mechanically milled in a high-energy attritor mill for 35 h. Ultra-fine tungsten powders and commercial Ni, Fe powders were consolidated into green compacts by using CIP method and liquid-phase sintering at 1465℃ for 30 rain in the dissociated ammonia atmosphere. Liquid-phase sintered tungsten heavy alloys using ultra-fine tungsten powders exhibit full densification (above 99% in relative density) and higher strength and elongation compared with conventional liquidphase sintered alloys using original tungsten powders due to lower sintering temperature at 1465℃ and short sintering time. The mechanical properties of sintered tungsten heavy alloy are found to be mainly dependent on the particles size of raw tungsten powders and liquid-phase sintering temperature.     

Microstructural control of and mechanical properties of mechanically alloyed tungsten heavy alloys

93W-5.6Ni-l.4Fe tungsten heavy alloys with controlled microstructures were fabricated by mechanically alloying of elemental powders of tungsten, nickel and iron by two different process routes. One was the full mechanical alloying of blended powders with a composition of 93W-5.6Ni-l.4Fe, and the other was the partial mechanical alloying of blended powders with a composition of 30W-56Ni-14Fe followed by blending with tungsten powders to form a final composition of 93W-5.6Ni-l.4Fe. The raw powders were consolidated by die compaction followed by solid state sintering at 1300°C for 1 hour in a hydrogen atmosphere. The solid state sintered tungsten heavy alloys were subsequently liquid phase sintered at 1445∼1485°C for 4-90 min. The two-step sintered tungsten heavy alloy using mechanically alloyed 93W-5.6Ni-l.4Fe powders showed tungsten particles of about 6-15 μm much finer than those of 40 um in a conventional liquid phase sintered tungsten heavy alloy. An inhomogeneous distribution of the solid solution matrix phase was obtained in the two-step sintered tungsten heavy alloy using partially mechanically alloyed powders. The two-step sintered tungsten heavy alloy using mechanically alloyed 93W-5.6Ni-l.4Fe powders showed larger elongation of 16% than that of 1% in the solid state sintered tungsten heavy alloy due to the increase in matrix volume fraction and decrease in W/W contiguity. Dynamic torsional tests of the two-step sintered tungsten heavy alloys showed reduced shear strain at maximum shear stress than did the sintered tungsten heavy alloys using the conventional liquid phase sintering.     

Microstructures of Sintered Mo-Cu Alloys with Mechanically Activated Powder

Mo-Cu alloy has been investigated for manyyears due to its excellellt properties such as electrical and thermal conductivity. Higher requirements are needed to enable the developmellt ofelectronic devices and semiconductor with greatpower and better properties [l], such as electrical and thermal conductivity, strength, hardness,especially linear eXPansion coefficiellt and gasproofproperty.The synthesis of adVanced Mo-Cu alloy requires new process. Melting is a classic method.For Mo-Cu allo…     

Measurement and Analysis of Liquid Density of NiCoAlMo Quarternary Alloys

用改良静滴法对钼浓度在0%到10%(质量分数)的NiCoAlMo四元合金的液态密度进行了测量,NiCoAlMo合金的Ni:Co:Al摩尔比与商用镍基超合金TMS75、INCO713、CM247LC和CMSX-4的Ni:Co:Al摩尔比接近(xNi:xCo:xAl=73:12:15)。结果表明:液态密度随温度的增加而减小,随合金中钼浓度的增加而增加;液态NiCoAlMo四元合金的摩尔体积随温度和合金中钼浓度的增加而增加,与理想混合相比,呈负偏差。由镍基二元合金中镍、钴、铝、钼4个元素的偏摩尔体积计算获得的NiCoAlMo四元合金的液态密度与实验测量密度吻合良好,表明在误差范围内,多元镍基合金的液态密度可以通过二元镍基合金中相应元素的偏摩尔体积进行预测估计。     

Cu/W-Ni/Ni多中间层的钨/钢扩散连接(英文)

采用铜箔/90W-10Ni(质量分数)混合粉末/镍箔多中间层,在加压5 MPa、连接温度1150°C、保温60 min的工艺条件下,对纯钨(W)和0Cr13Al铁素体不锈钢进行真空扩散连接。利用SEM、EDS、电子万能试验机及水淬热震实验等手段研究接头的微观组织、成分分布、断口特征、力学性能及抗热震性能。结果表明,连接接头由钨母材/Cu-Ni合金层/W-Ni复合材料层/镍层/钢母材五部分组成。接头中的W-Ni复合材料层由90W-10Ni混合粉末固相烧结而生成,其组织均匀、致密。W-Ni复合材料层与钨母材以瞬间液相扩散连接机制来实现良好结合。接头剪切强度达到256 MPa,断裂均发生在W-Ni复合材料层与镍层的结合区域,断口形貌呈现为韧性断裂。经过60次700°C至室温的水淬热震测试,接头无裂纹出现。