含MoS2的Ni基合金摩擦学特性的研究

用粉末冶金法制备了Ni基合金材料,测试了合金机械性能及其在室温下的摩擦磨损性能,同时还探讨了其耐磨机理.研究结果表明,MoS2质量分数为10%～15%的合金具有较好的机械和摩擦磨损综合性能.该合金主要由Ni基固溶体、定比化合物CrxSy、MoS2和Mo2S3等相组成,在室温下摩擦表面形成含硫化合物复合膜而起润滑作用.     

Cu对镍基合金热态磨损能力的增强作用

采用粉末烧结技术制备添加不同含量Cu粉的镍基合金。利用金相显微镜、SEM、XRD等仪器对合金的组织进行分析,并对其硬度、耐磨性进行研究,利用MMW-1型万能摩擦磨损试验机对合金在不同热态时的磨损进行测试。结果表明:向Ni基合金中添加微量的Cu可细化镍基合金的晶粒,能生成Ni Cu相和Cr Cu相并牢靠镶嵌在基体中,起润滑作用,改善镍基合金的磨损性能,当Cu含量为1%时镍基合金性能最优。     

稀土CeO_2对W-Ni-Fe高比重合金摩擦磨损性能的影响

采用高能球磨和放电等离子体烧结方法制备了W-4.9Ni-2.1Fe-xCeO_2高比重合金,通过XRD、SEM、显微硬度计及摩擦磨损试验机等研究了稀土CeO_2添加量对W-Ni-Fe高比重合金物相、显微组织及摩擦磨损行为等的影响。结果表明,微量稀土氧化物掺杂后,W衍射峰出现不同程度的宽化现象,晶粒得到细化,生成的复合稀土相Ce_xW_yO_z可以促进Ni、Fe在W晶格中的固溶。随着稀土含量的增加,显微硬度不断减小,相对密度先增大再减小,当添加量为0.4%(质量分数,下同)时,相对密度达到最大。稀土氧化物CeO_2的添加能降低合金试样的摩擦磨损性能。当添加量为0.4%时,粘结相分布相对较均匀,W-W之间的界面结合强度较高,合金致密化程度最高,致使磨损曲线比较稳定,对材料耐磨性能的降低效果最小。     

AB5-AB2复合合金电极的微观结构和活化性能

根据AB5型稀土基合金的活化性能优良及对氢化和氢化物分解过程具有催化作用的特点 ,将Zr0 .9Ti0 .1 (Mn0 .35Ni0 .6 5) 2 AB2 型Laves相合金与AB5型混合稀土合金进行机械球磨处理 ,制备了AB5 AB2 复合合金。研究了复合合金的微观结构和电化学性能 ,结果表明 :在AB5 AB2复合合金中 ,AB5粒子与AB2 粒子在表面处相互镶嵌在一起 ,并仍保持原来的晶体结构。复合合金电极的活化周期从AB2 合金的 11周减少到 4周 ,最大放电容量从 14 1mAh·g- 1 增加到 2 18mAh·g- 1 ,而且在活化初期表现出协同效应。     

粉末冶金技术2002年第1～6期总目次

文　　题期　页·研究与开发·　　　超细晶粒硬质合金粉的成形特征 1　 3快速凝固ＡｌＳｉ17Ｆｅ6 Ｃｕ4 .5Ｍｇ0 .5合金的组织　及性能 1　 8稀土化合物对粉末冶金镍基合金摩擦磨损　性能的影响 2　 67Ｔｉ-Ｗ -Ｃ体系燃烧合成产物颗粒形貌分析 2　 71Ｍｏ -Ｌａ2 Ｏ3 烧结坯的韧化机制研究 2　 75金属雾化过程中气体流场动力学行为 2　 79纳米级超细ＷＯ3 粉的还原动力学特征 3147喷射成形镍基高温合金冷却速度的评价 315 1金属注射成形石蜡基粘结剂主体聚　合物的研究 315 4Ｔｉ(Ｃ ,Ｎ)基金属陶瓷功能梯度材料的制备 4 195Ｂｉ对Ａｇ -…     

部分TiAl基合金的抗氧化性评价

用年腐蚀深度公式计算了5种TiAl基合金在700℃-1000℃高温条件下设计寿命为1年或半年的腐蚀程度,对其抗氧化进行了评价,并与其它耐热材料作了比较。结果显示,二元TiAl基合金的抗氧化性强于三元TiAl－Cr合金,前者在800℃左右,后者低于800℃;二元TiAl基合金中T -50Al及Ti-52Al的抗氧化性优于Ti-48Al合金,三元TiAl-Cr合金中Ti-48Al-4Cr的抗氧化性优于Ti-48Al-1Cr合金。5种TiAl基合金的抗氧化性均不如Ni基合金及Ni-Al系化合物,但比Ti3Al及常规钛合金好。     

用稀土氧化物电渣重熔0Cr25Al5电热合金的研究

用Fe-Cr-Al作为电热材料与Ni—Cr相比具有一系列的优点:使用温度高,电阻率大,在氧化气氛中使用寿命比Ni—Cr高,此外Fe—Cr—Al是铁基合金不加Ni,所以Fe—Cr—Al系是符合我国资源情况的电热合金,从而得到了大量的推广与使用。往0Cr25Al5合金中加入稀土金属对提高寿命的效果极为显著。当稀土含量为0.034～0.075％时,0Cr25Al5合金在1200℃的快速寿命由原来的180小时提高到300小时。稀土作用如此之大,再加上我国稀土资源丰富,因此进一步研究稀土在该合金中的应用,使其主要性能指标赶上或超过国际先进水平,就显得更为重要了。     

用稀土改性钴基合金激光熔覆层

对激光熔覆钴基稀土合金涂层进行了研究。稀土对钴基合金变质作用明显。一方面 ,细化组织 ;另一方面 ,增加合金化合物的比例。在本试验条件下 ,稀土含量增加 ,合金的硬度增加 ,但有脆性增大趋势。当稀土含量为 0 .4 %时 ,耐酸蚀性最佳 ,比原合金提高了 35 % ;含量为 0 .8%时 ,其耐磨性、强耐碱蚀性及抗氧化性分别比原合金提高 30 % ,4 5 %和 4 0 %。     

稀土Y对Mg-15Al合金组织及摩擦磨损行为的影响

通过合金制备、微观分析和摩擦磨损测试等手段,研究了不同含量的稀土元素Y对Mg-15Al合金相微观组织和摩擦磨损性能的影响。实验结果表明,加入钇后,Mg-15Al合金的α-Mg晶粒明显细化,α+β共晶组织由粗大的网状变得分散、细小,钇与铝形成稳定的Al2Y化合物,钇的加入量为0.8%时,组织细化效果最好,此时晶粒尺寸最小为23.05μm。当钇加入量超过0.8%时,α-Mg晶粒又变大,力学性能下降。稀土镁合金的摩擦磨损特性明显优于基体合金,稀土元素的加入增强了磨损表面氧化膜的稳定性,提高了稀土镁合金的承载能力,有效延迟了由轻微磨损向严重磨损的转变过程。     

Au-19.25Ag-12.80Ge钎料的焊接性能研究

根据Au-Ag-Ge三元相图, 制备了新型Au-19.25Ag-12.80Ge(%, 质量分数)钎料合金.利用DTA, Sirion200场发射扫描电镜对钎料的熔化特性及显微组织进行分析, 并对其与纯Ni的润湿性加以研究.结果表明: Au-19.25Ag-12.80Ge钎料合金的熔化温度为446.76～494.40 ℃, 结晶温度区间为47.64 ℃; 焊接温度在510～550 ℃范围内时, Au-19.25Ag-12.80Ge钎料合金与Ni基体具有良好的铺展性和润湿性, 在熔化钎料前沿有润湿环现象出现, 钎料合金与Ni基体之间形成了一条连续的金属间化合物层, 能谱分析表明该金属间化合物层为Ge3Ni5金属间化合物, 由于该化合物层较脆, 故应控制焊接工艺以获得连续均匀且厚度适当的金属间化合物层; 对于本钎料合金而言, 焊接温度530 ℃, 保温时间10 min可获得较理想的焊接界面.     

Friction and Wear Characteristics of Mg-Al Alloy Containing Rare Earths

The influence of rare earth on the friction and wear characteristics of magnesium alloy AZ91 and AM60 were studied. The results show that the wear resistance properties of rare earth magnesium alloys are better than those of matrix alloy under the testing conditions. The anti-wear behaviour of AZ91 alloy is much better than that of AM60 alloy. In dry sliding pmcess, magnesium alloys undergo a transition from mild wear to severe wear. The addition of rare earths refine the structure of alloys, improve the comprehensive behaviors of magnesium alloys,increase the stability of oxidation films on worn surfaces,enhance the loading ability of rare earth magnesium alloys,and delay the transition from mild wear to sevre wear effectively.     

Rare earth ceramic cutting tool and its cutting behavior when machining hardened steel and cast iron

The addition of rare earth element yttrium played an important role in the improvement of both mechanical properties and wear resistance of Al2O3/(W,Ti)C ceramic cutting tool material.Mechanical properties especially the fracture toughness and flexural strength were obviously increased when a suitable amount of the yttrium were added.Wear resistance of the developed rare earth ceramic cutting tool material was higher than that of the corresponding materials without rare earth in the machining of the hardened 45# carbon steel and cast iron HT20-40.Wear modes of the Al2O3/(W,Ti)C rare earth ceramic tool materials were mainly flank wear and crater wear accompanied with slight notch wear when machining the hardened carbon steel.Wear mechanisms were major abrasive wear at low cutting speed and adhesive wear at high cutting speed.Wear modes were nearly the same except that the adhesion phenomenon in the crater area was intensified when machining cast iron.The flank wear area was relatively smooth with no obvious plowing phenomenon which was possibly concerned with the workpiece of low hardness and the adhesion phenomenon at high cutting temperature.     

Fe3Al基合金的高温耐冲蚀磨损性能

利用通以含高浓度ＳＯ２和ＳｉＯ２细颗粒气流的专门装置，研究了Ｆｅ３Ａｌ基金属间化合物的耐高温腐蚀磨损性能。试验结果表明，Ｆｅ３Ａｌ基金属间化合物的抗高温磨损性能优于钴基合金（ＣｏＦｅ１５Ｃｒ２５Ｓｉ７）、高铬镍铁基耐热合金（ＦｅＣｒ２８Ｎｉ７）以及表面喷涂Ｎｉ６０的１８－８不锈钢。     

稀土球化剂的喷射冶金特性

比较了镁和稀土的球化能力及效果。当稀土残留量与镁残留量之比为3:1时,两种球化剂的球化能力相等。原铁水成份为C ≥ 40%,C·E ≥ 57%,稀土处理后,铁水中S ≤ 0.01%,RE ≥ 0.1%时,白口倾向与镁处理结果没有差别。
在100kg铁水包内进行稀土喷射冶金的结果表明,稀土处理脱硫速度快,效率高,脱硫限度接近热力学平衡常数。所得铁水中终硫含量都在0.01%以下,有利于获得良好的球化效果。将硅铁粉与稀土混合喷入可使脱硫、球化和孕育3个过程一次完成,这也是传统方法不具备的特点。     

Research and Development of Rare Earth Advanced Materials in China

ＲｅｓｅａｒｃｈａｎｄＤｅｖｅｌｏｐｍｅｎｔｏｆＲａｒｅＥａｒｔｈＡｄｖａｎｃｅｄＭａｔｅｒｉａｌｓｉｎＣｈｉｎａＷａｎｇＤｉａｎｚｕｏ（王淀佐），ＷａｎＱｕｎ（万群），ＹａｎｇＹｕｃｈｕｎ（杨遇春）（ＧｅｎｅｒａｌＲｅｓｅａｒｃｈＩｎｓｔｉｔｕｔｅ...     

稀土La对粉末冶金钛合金组织和力学性能的影响

在Ti-Fe-Mo合金中以LaH2和LaB6两种形式引入稀土La,制备含La的粉末冶金钛合金,研究La的添加量对钛合金烧结行为以及组织与力学性能的影响,探讨合金中La的存在形式及其在烧结过程中的作用机理。结果表明,钛合金相对密度随LaH2添加量(质量分数)的增加而升高,当LaH2的添加量达到0.6%后,钛合金的相对密度不再发生明显变化;但随着LaB6添加量的增加先升高后降低,在LaB6添加量为0.15%时出现峰值。添加LaH2的钛合金中,稀土元素主要以La2O3颗粒的形式存在,随La含量增加,颗粒发生长大;而在添加LaB6的合金中,烧结反应产物主要是纤维状的TiB、具有规则外形的La2O3颗粒以及含Ti和O的富La絮状颗粒。随LaH2和LaB6的添加量增加,合金的室温抗拉强度和伸长率均先升高后降低。LaH2的添加量达到0.6%时出现强度峰值,添加量达到0.3%时出现伸长率的峰值;而LaB6的添加量达到0.15%时抗拉强度和伸长率均出现峰值。     

Effects of Doping on Magnetic Properties of YCo5-xFex and YCo5-xAgx——First Principles Calculation

One way of improving the magnetic properties of RECo5 (RE=rare earth) compounds, especially the magnetic anisotropy energy (MAE), is to dope them with some additives such as Fe, Ni, Cu. Those dopants bring changes in both lattice geometry and magnetic properties of the compounds. In this paper, the effects of doping on YCo5-xFex and YCo5-xAgx were studied in two simple but effective ways: first, the geometric effect induced by doping and then, the pure doping role namely without any geometric changes. The calculated results indicate that the magnetic moments of Co show a transition from a high spin state to a low one with the change of the volume of the cell in all YCo5, YCo3Fe2 and YCo3Ag2 alloys. The change of c/a ratio with constant lattice parameter a also influences drastically the magnetic moments and the MAE. As the geometric structure is not changed, it is found that the doping effects of magnetic element Fe and non-magnetic element Ag are quite different.     

高容量稀土基贮氢合金的研究

以金属RE、La、Ni、Co、Mn、Al作为稀土基贮氢合金的原料,制备了一系列不同成分的贮氢合金,进行了相应的组织结构分析及电化学性能的测试,研究了不同La、Co添加量对合金相结构与电化学性能的影响,选择确定了合适的合金配方,为生产高容量Ni-MH电池的负极材料提供了依据.     

稀土氧化物粒子对钼合金粉末冶金过程及力学性能的影响

试验研究了掺杂La2O3、Y2O3、CeO2稀土氧化物颗粒对钼合金的粉末物性、烧结进程、制品的烧结致密度及压力加工丝材的室温力学性能的影响规律。试验结果表明,掺杂稀土氧化物粒子细化了钼粉的粒度,降低了松装密度和粒度分布范围,同时导致粉末团聚现象增多;稀土氧化物粒子延迟了钼合金的烧结进程,降低了烧结制品的致密度,同时细化了烧结体晶粒尺寸。稀土氧化物粒子以弥散强化和细晶强化的形式,提高了钼合金丝的室温强度。CeO2显著提高了钼合金丝的室温韧性,La2O3、Y2O3则降低了钼合金丝的室温韧性。     

Effects of Rare Earths on Properties and Microstructure of Automotive Friction Materials

Rare earth compounds as modifiers used widely in modern friction materials can enhance the interracial binding of constituents of materials and improve the comprehensive properties of materials evidently. However, there are still few reports on application of rare earth in automotive friction materials. In order to study the effect mechanism of rare earths in friction materials, a rare earth compound was selected as additive and the effects of materials doped with or without rare earth on friction and wear properties of materials were studied. The microstructure and worn surface morphology were observed by scanning electron microscopy and the macro performance was discussed. Worn surface element constitution of materials was analyzed by energy dispersive spectroscopy. Effect mechanism of rare earths on friction and wear behaviors of friction materials were discussed. The results show that doping rare earths in friction materials can stabilize friction Coefficient, lower the wear rate of materials and increase the impact strength of materials. The flexibility and fracture resistance of materials is greatly improved. Worn surface of materials doped with rare earth is compact and the surface adhesion is greatly enhanced.