O.P.P
,
ey
材料科学技术（英）
Two commercial grade aluminum based immiscible bearing alloys were spray-deposited using convergent-divergent type of nozzle. The processing parameters for spray-deposition were adjusted in such a way that most of the droplets arrived on the deposition substrate in either liquid or semi-liquid state. The microstructural features of spray-formed and as-cast alloys are compared. In spray-formed alloys equiaxed grains were observed. The cell boundaries and intercellular regions were observed to be decorated with sub-micron sized particles whereas in normal casting the second phase was observed to be segregated along grain boundaries. The morphology and distribution of second phase were observed to have similarity with those in over-spread and atomized powders produced under similar processing conditions. The microstructural features observed with variation in spray conditions are discussed in detail.
关键词:
Spray deposition
,
null
,
null
,
null
陈玮
,
姚长江
,
尹周澜
,
刘新红
耐火材料
doi:10.3969/j.issn.1001-1935.2008.04.009
分别对反应前后的p-Al2O3进行XRD及SEM分析,确定反应前后Al2O3的物相及显微结构变化;测定加入添加剂前后浆体温度与时间的关系,从而确定添加剂对p-Al2O3水化速度的影响;测定加入添加剂前后浆体的黏度变化,从而测定出添加剂对p-Al2O3水化过程的影响.结果表明:1)p-Al2O3属于无定形态;2)在没有添加剂的情况下,p-Al2O3的水化速率很快,同时释放出大量热量,水化产物主要是一水软铝石、三水铝石和拜耳石;3)加入碳酸钠及六偏磷酸钠的混合物为添加剂后,p-Al2O3的水化速率显著降低,释放出的热量显著降低,水化产物主要是一水软铝石.
关键词:
p - 氧化铝
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水化硬化
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不定形耐火材料
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结合剂
Journal of Alloys and Compounds
The subsolidus phase relations in the system La2O3-B2O3-P2O5 were investigated. The system can be divided into 12 three-phase regions. There are nine binary compounds and one ternary compound in this system. The ternary compound La7O6(BO3)(PO4)(2) has a monoclinic structure, space groups P2(1)/n, with lattice constants a = 7.0172 Angstrom, b = 17.9125 Angstrom, c = 12.6500 Angstrom, beta = 97.516 degrees, V = 1576.39 Angstrom(3), and Z = 4.
关键词:
La2O3-B-3-B2O3-P2O5 system;phase relations;ternary compounds
ZHOU Guanghong
,
DING Hongyan
,
ZHOU Fei
,
ZHANG Yue
钢铁研究学报(英文版)
NiPnano Al2O3 composite coatings were deposited by electroless plating, and their microstructures were observed by SEM (scanning electron microscope). The microhardness and the wear resistance of the NiPnano Al2O3 composite coatings were measured using microhardness tester and blockonring tribometer, respectively, and the comparison with those of NiP coatings or NiPmicro Al2O3 coating was given. The influences of aging temperature on their hardness and wear resistance were analyzed. The results showed that the nano Al2O3 particles were distributed uniformly in the NiPAl2O3 coatings. Among three kinds of NiP based coatings, the hardness and wear resistance of NiPnano Al2O3 coatings were largest, and the maximum values could be obtained at 400 ℃. This indicated that the precipitation of nano Al2O3 particles would improve the hardness and wear resistance of the NiP coatings.
关键词:
composite coating;nano Al2O3;aging treatment;mechanical property
Lihong HAN
,
Jitai NIU
,
Darning JIANG
,
Tsunernichi Imai
材料科学技术（英）
The superplasticity of an Al(2)O(3)p/6061Al composite, fabricated by powder metallurgy techniques, has been investigated. Instead of any special thermomechanical processing or hot rolling, simple hot extrusion has been employed to obtain a fine grained structure before superplastic testing. Superplastic tensile tests were performed at strain rates ranging from 10(-2) to 10(-4) s(-1) and at temperatures from 833 to 893 K. A maximum elongation of 200% was achieved at a temperature of 853 K and an initial strain rate of 1.67x10(-3) s(-1). The highest value obtained for the strain rate sensitivity index (m) was 0.32. Differential scanning calorimeter was used to ascertain the possibility of any partial melting in the vicinity of optimum superplastic temperature. These results suggested that no liquid phase existed where maximum elongation was achieved and deformation took place entirely in the solid state.
关键词:
赵宏生
,
李艳青
,
周万城
,
罗发
无机材料学报
doi:10.3321/j.issn:1000-324X.2003.01.004
采用红外光谱(IR)和X射线光电子能谱(XPS)等方法研究了PbBr2-PbF2-P2O5系铅卤磷酸盐玻璃的结构.结果表明,Pb2+离子在玻璃中起着网络修饰阳离子和网络形成体的双重作用.当P2O5含量为60mol%时,Pb2+离子主要是作为网络修饰体;当P2O5含量降低到50 mol%时,一部分pb2+离子能够进入玻璃网络形成PbO4]四面体或P-O-Pb键.Br-和F-离子达到一定浓度时就会进入玻璃网络,形成[PO4-nXn](X=Br或F,n=0～4)四面体使磷酸盐链长变短.玻璃中P2O5的含量不变时P-O-P键的比例也基本保持不变;当P2O5的含量降低时,P-O-P键和P-O-键的含量都减少,P-O-Pb键的含量则明显增加.
关键词:
铅卤磷酸盐玻璃
,
红外光谱
,
X射线光电子能谱
,
结构研究
周寒梅
,
包燕平
,
林路
中国冶金
以CaO-Si()2-FetO-P2O5四元渣系为研究对象,结合理论计算和热态试验综合分析P2O5质量分数变化对该四元渣系物相组成以及富磷相的影响.应用Factsage软件equilib模块计算CaO-SiO2-FetO-P2O5四元渣系在400～1800℃温度区间的多相平衡,再结合SEM+EDS与XRD对热态试验结果进行分析知,随着渣中P2O5质量分数的增加,富磷相中Ca3 (PO4)2的质量分数随之增加.此外,P是以nC2S-C3P固溶体的形式存在于富磷相中,但当渣中P2O5质量分数达到18％时,富磷相中的P将以Ca3(PO4)2的形式独立存在.热态试验的分析结果进一步验证了Factsage的理论计算结果.
关键词:
P2O5
,
Factsage
,
富磷相
,
物相
王希涛
,
钟顺和
应用化学
doi:10.3969/j.issn.1000-0518.2001.11.009
用共沉淀法和溶胶-凝胶法制备了Fe-P-O催化剂,用DTA-TG、TEM、XRD、IR和TPR等方法对微粒组成、结构进行了表征.以分子探针IR方法考察了乙烷在Fe-P-O催化剂表面上的吸附性能.结果表明,溶胶-凝胶法制备的Fe-P-O催化剂为超细非晶态结构,粒子分布为10～20 nm,其比表面、晶格氧的活泼性均大于共沉淀法制备的晶态Fe-P-O催化剂.乙烷能以分子态吸附于催化剂表面P=O键上,随吸附温度升高,乙烷吸附强度逐渐增大;乙烷在非晶态Fe-P-O催化剂上的吸附量和吸附强度均大于晶态Fe-P-O催化剂.
关键词:
Fe-P-O催化剂
,
共沉淀法
,
溶胶-凝胶法
,
乙烷化学吸附
吴鼎芬
金属学报
用最大气泡法和秤重法分别地测定了液态和固态的FeO-Fe_2O_3-P_2O_5和CaO-P_2O_5渣系的密度。密度随系统中FeO+Fe_2O_3或CaO浓度的增加而升高。把实验结果结合本文作者以前研究过的FeO-Fe_2O_3-CaO系的密度值并外插到纯FeO处,得FeO在1400℃时密度应为4.7±0.15克/厘米~3,在25℃为5.85克/厘米~3。把4.7克/厘米~3作为FeO在1400℃时的密度,校正了本文作者以前导出的一个计算工业炉渣密度的半经验公式。 此外,根据研究结果,还讨论了分层渣系FeO-Fe_2O_3-CaO-P_2O_5的密度。
关键词:
