共查询到19条相似文献,搜索用时 109 毫秒
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为了提高金刚石锯片的性能,对铜基(含钴)与铁基(含铜)胎体进行了机械合金化(球磨)前后的烧结工艺探索,研究发现,球磨胎体金属粉末能使刀头硬度、抗弯强度提高。对铁基(含铜)球磨与未球磨以及生产使用的成熟配方(铜基含钴)三种金刚石锯片,进行了工业锯切实验,测试三种锯片的耐磨性与锋利度,结果表明,球磨金属粉末可以综合提高铁基(含铜)锯片的性能。成功研制出成本明显降低、性能较高的新产品。 相似文献
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将W80Cu20(n(W):n(Cu)=4:1)混合粉末在QM-BP式行星式高能球磨机中球磨进行机械合金化,研究了不同球磨时间对W-Cu混合粉末组织的影响.采用XRD和SEM对不同球磨时间的粉末进行分析,结果显示随着球磨时间的增加,混合粉末产生合金化效果不断增强,Cu固溶于W中,并且晶粒尺寸得到一定的细化. 相似文献
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以工业WC粉、Co粉和Cr_3C_2粉为原料,用行星式高能球磨机制备了WC-Co-Cr_3C_2复合粉末。采用X射线衍射、扫描电镜和光电子能谱等对粉末进行了分析。结果表明,球磨12h后复合粉末的粒度可达0.1μm左右,Co均匀分布且部分包覆在WC颗粒表面,处于亚固溶状态。 相似文献
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机械合金化制备高纯NiAl粉末 总被引:1,自引:0,他引:1
采用机械合金化方法制备NiAl粉末,用XRD和SEM对合成样品进行物相组成和形貌分析,研究了球磨时间和转速对NiAl粉末合成的影响规律.结果表明:球料比6:1,转速500 r/min时,球磨5h后NiAl合成反应基本完成,但由于铝粉的损失,导致合成粉末物相不纯,有少量Ni3Al存在;转速影响机械合金化方法制备高纯NiAl粉,选择合适的转速(365 r/min)可以制得纯NiAl粉. 相似文献
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通过分析球磨参数对机械合金化粉末的影响,实验发现,随着高能球磨时间的延长,不同元素晶格常数变化率稍有不同,均呈增加趋势。当Ti-9Mg合金的转速为170 r/min时,Ti的X衍射峰宽度明显宽于转速为110 r/min时的情况,研究结果对于进一步优化合金粉末制备工艺和提高材料性能具有一定的指导意义。 相似文献
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机械合金化制备W-Ni-Cu纳米复合粉末的研究 总被引:1,自引:0,他引:1
采用机械合金化(MA)制备W—Ni—Cu纳米复合粉末,对粉末的晶粒尺寸、粒度、松装密度、振实密度进行了测定和分析,并研究了过程控制剂(PCA)对粉末性能的影响。 相似文献
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以金属Zr、Cu和Al为原料,通过真空熔炼和气体雾化制备Zr-Cu-Al合金粉末,再经高能球磨得到Zr50Cu40Al10非晶合金粉末。采用氮/氧分析仪、X射线衍射仪(XRD)、扫描电镜(SEM)和热分析仪(DSC)对其非晶形成能力及晶化行为进行研究。结果表明,球磨120h后可获得Zr50Cu40Al10非晶合金粉末,且随球磨时间增加,粉末的颗粒尺寸逐渐减小,90h后达到亚微米级。球磨过程中由于铁的增加,使合金的结构"混乱度"增加、负混合热增大,因而热稳定性增强,其过冷区间ΔTx为62K,约为雾化法制备的非晶合金粉末的2倍。此外,采用非等温晶化方法,用KISSINGER方程计算出机械合金化Zr50Cu40Al10非晶合金的玻璃转变和初始晶化的表观激活能分别为152.6kJ/mol和172.4kJ/mol,远小于相应的气体雾化法制备的Zr50Cu40Al10非晶合金粉末表观激活能,其原因是粉末中氧含量和体系自由能较高。 相似文献
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Effect of mechanical alloying on the properties of powder metallurgy composites of the Al-SiC system
L. R. Vishnyakov N. P. Onis’kova A. N. Gribkov I. M. Romashko 《Powder Metallurgy and Metal Ceramics》1997,36(11-12):599-603
The process of mechanical alloying used in the powder metallurgy processing of Al-SiC materials was applied to the treatment of a mixture of aluminum and silicon carbide particles in an attritor. Optimal processing led to the formation of composite pellets containing SiC particles uniformly distributed in an aluminum alloy matrix. Subsequent compaction of these mechanically alloyed pellets produced material with ultimate strength 587 MPa, elastic modulus 10.5 GPa, and elongation 2.1%. Comparison of measured with calculated values of the elastic modulus indicated a high degree of matrix continuity in the structure of the mechanically alloyed composite material. 相似文献
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研究高能球磨制备Nb/Al化合物的工艺,探索在高能球磨过程中Nb、Al形成化合物的机理.结果表明,通过高能球磨可获得Al在Nb中的固溶体,固溶度与球磨转速和球磨时间成正比,并发现选用硬脂酸作为添加剂有利于Nb/Al的机械合金化.对高能球磨中机械合金化的机理进行了讨论,指出高能球磨产生的高比表面能和高密度晶体缺陷大大降低... 相似文献
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机械合金化制备纳米晶硬质合金粉的进展 总被引:2,自引:0,他引:2
综述了机械合金化制备纳米晶硬质合金粉的概况、原理和两种用该方法制备纳米晶硬质合金粉的方式。并分析了各工艺参数对机械合金化制备纳米晶硬质合金粉的影响。该技术工艺简单,可实现工业化生产,是一种很有应用前途的方法。 相似文献
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A. Nadjafi Maryam Negari R. S. Mamoory A. Simchi N. Ehsani 《Powder Metallurgy and Metal Ceramics》2007,46(9-10):423-428
Microwave energy is highly efficient for heating and processing different materials. In recent years, this type of heat transfer has been used in sintering process. Rapid and highly efficient heating, time and energy saving, and improved properties of sintered materials are advantages of microwave sintering. In this paper, Fe and Fe-Cu powder compact samples (cylindrical and bone shapes) are sintered both in microwave and electrical tube furnaces. The microwave generator has 2.45 GHz frequency and 1 KW power. Times are selected in the range of 5–25 min for microwave sintering and 5–40 min for electrical heating. The sintering temperature is set at 1120°C. Samples are sintered in the reducing atmosphere of 95% N2 + 5% H2 mixture. The density, hardness, and tensile strength of the samples are measured. The results are compared. The results show that the microwave-sintered materials have a finer microstructure. The microwave-sintered materials have 6–8% higher density, 5–10 HV5 higher hardness, and about 10% higher tensile strength than conventionally sintered materials. 相似文献
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V. S. Voropaev G. Ya. Kalutskii O. V. Ivashchenko 《Powder Metallurgy and Metal Ceramics》1988,27(6):449-453
Translated from Poroshkovaya Metallurgiya, No. 6(306), pp. 45–49, June, 1988. 相似文献
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Mechanical alloying of two aluminum alloy powders to form composite A1-A12O3 powders has been studied. Changes in powder microstructure with processing are reported and interpreted. Mechanical alloying
proceeds by the continual cold welding and fracturing of the constituent powder particles when subjected to the large compressive
forces of a high speed mill. A suitable organic surfactant must be added so that a balance between cold welding and fracturing
is obtained. The organic surfactant is embedded and finely distributed in the powder particles during mechanical alloying
and is converted to discrete A14C3 particles after hot pressing. The establishment of steady state processing conditions, characterized by equiaxed powder particles,
a constant particle size distribution and a saturation hardness, is found to depend on the size distribution of the initial
powders. The oxide particles formed and distributed during mechanical alloying are equiaxed, small (30 nm) and homogeneously
distributed with a volumetric center to center distance of about 60 nm.
Formerly Graduate Research Assistant in the Department of Materials Science and Engineering at Stanford. 相似文献
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在高纯氩气保护下采用高能球磨法对原子组成为Fe44Co44Zr3.5Nb3.5B4Cu1的混合粉末进行机械合金化(MA)实验,成功地制取了非晶合金粉末.利用X射线衍射(XRD)、扫描电镜(SEM)、差热分析(DTA)对其进行测试,结果表明:Fe-Co系的混合粉末在MA过程中,通过原子之间的相互固溶、扩散可形成非晶态.此非晶合金的形成是晶粒细化、球磨过程中的缺陷、应力和致密堆垛结构等多种因素综合作用的结果,这与机械合金化的合成机理之一的扩散型机制相吻合.用非晶化的热力学条件判据和动力学条件判据对此合金进行计算,其结果也表明此合金已非晶化. 相似文献