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In-situ ZrB2/AZ91D magnesium matrix composite was successfully synthesized with Al/K2ZrF6+NH4BF4 by means of Direct Melt Reaction. The fabricated ZrB2 /AZ91D magnesium matrix composite through direct melt mixing method was investigated. Results from X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDS) confirmed the existence of ZrB2 particles in the AZ91D alloy, and most ZrB2 particles were in the size range of just several microns, some even to 100 nm. The cast specimens were studied through corrosion testing and heat treatment. The average grain size of AZ91D decreased markedly from about 250 μm to 50 μm. In addition, the shape and size of the β-Mg17Al12 phase as well as the morphologies of primary α-Mg in the magnesium matrix composite were greatly changed. The network structure of the β-Mg17Al12 phase was broken into small blocks and the size of α-Mg decreased significantly.

In-situ ZrB2/AZ91D magnesium matrix composite was successfully synthesized with Al/K2ZrF6+NH4BF4 by means of Direct Melt Reaction. The fabricated ZrB2 /AZ91D magnesium matrix composite through direct melt mixing method was investigated. Results from X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDS) confirmed the existence of ZrB2 particles in the AZ91D alloy, and most ZrB2 particles were in the size range of just several microns, some even to 100 nm. The cast specimens were studied through corrosion testing and heat treatment. The average grain size of AZ91D decreased markedly from about 250 μm to 50 μm. In addition, the shape and size of the β-Mg17Al12 phase as well as the morphologies of primary α -Mg in the magnesium matrix composite were greatly changed. The network structure of the β-Mg17Al12 phase was broken into small blocks and the size of α-Mg decreased significantly. [ABSTRACT FROM AUTHOR]

Abstract: The interface structures of the (Al2O3 +Al3Zr)/A356 nanocomposites fabricated by magneto-chemistry in situ reaction are investigated by TEM technologies. The results indicate that the Al3Zr/Al, Al2O3/Al and Al2O3/Si interfaces are net and smooth, no interface reactants are observed. The vector relations for Al3Zr and α-Al phases are: , , and , for α-Al2O3 and Si phases. The misfit degree δ for the (0001) crystal plane of the α-Al2O3 phase and the (110) crystal plane of the Si phase is 5.08%. The interface fit-relations for the Al2O3 phase and the Si phase are that the Si phase can be nucleated on theα-Al2O3 phase. These contribute to the perfect properties of the nanocomposites. [Copyright &y& Elsevier]

Abstract: Al–4Cu matrix composites reinforced by ZrB2, Al2O3 and Al3Zr particulates are synthesized using a magneto-chemical melt reaction. Using an electro-magnetic assisted melt reaction results in a uniform distribution of in situ particles with no indication of clustering and an equivalent diameter in the range of 80nm–2μm. Comparing to the Al–4Cu alloy, the mechanical properties, the wear weight loss and the wear resistance of the composites are significantly enhanced. In particular, the increases in σ uts and σ y for the as-prepared composites with a 15% particulate-volume-fraction (PVF) are up to 47.3% and 53.7%; the decrease in wear weight loss from 89.078 to 46.385mg is obtained, and the wear weight resistance R relat. reaches 2.0573. [Copyright &y& Elsevier]

Abstract: The (Al3Zr+ZrB2)/Al composites were fabricated from Al-K2ZrF6-KBF4 system by magneto chemistry in situ reaction technology. The effects of molten temperature on the morphologies of in situ Al3Zr and ZrB2 particles were investigated by SEM analysis and the dry sliding wear properties of the composites by wear tests. The XRD results show that the components of the as-prepared composites consist of Al3Zr, ZrB2 and α-Al phases. The SEM analysis indicates that the morphologies of Al3Zr are sensitive to the temperature of the aluminum molten. When the temperatures were 1123, 1173, 1223 and 1273K, the morphologies of the Al3Zr with sphericity-shape, tetragon-shape, rod-shape and fiber-shape were observed, respectively; and the ones of ZrB2 showed no obvious diversity. Especially, when the temperature is 1273K, the size of the Al3Zr with nano-fiber shape is about 180nm in diameter. The dry sliding wear tests show that the wear weight loss of the S1, S2, S3 and S4 specimens shows no obvious difference with the sliding time of 15min. With the increase of the sliding time, the wear weight loss increases. At a given sliding time, the wear weight loss of the specimens varies with the following order: S1

Abstract: In situ Al–xwt.%(K2ZrF6–KBF4) (x =10, 15, 20, 25) composites reinforced by Al3Zr and ZrB2 particles were prepared via magnetochemistry in situ reaction and the dry sliding wear properties of the composites were investigated. The XRD results showed that the components of the as-prepared composites consist of Al3Zr, ZrB2 and α-Al phases. The SEM analysis indicated that ZrB2 and Al3Zr reinforcement particles were distributed uniformly in the aluminum matrix. The morphologies of ZrB2 and Al3Zr particles present in regular hexagon and tetragonal shapes, and the sizes were about 0.3–0.5μm, respectively. Wear test results showed that the values of wear weight loss of the composites decrease with the increase of x under a given sliding time and the load of 100N. The wear resistance R changed with variations of the sliding time stages, applied load and x. In particular, when x =25, the wear weight loss under a sliding time of 120min and R under the intermediate wear-sliding stage were 0.245 and 4.772 to that of the A356 alloy, reached 33.642mg and 5.114, respectively. [Copyright &y& Elsevier]

Abstract: Amorphous and crystalline hydrogen storage alloys of the composition NdMgNi4− x Co x (x =0.0, 0.2, 0.4, 0.6, 0.8, 1.0) were prepared by mechanical alloying and their electrode properties were investigated systematically by a simulated battery test. It was found that the maximum discharge capacity of the amorphous alloys was much higher than that of the crystalline ones, and the cycle life of the negative electrode changed with x from 0.0 to 1.0, and especially when x =0.4, the alloy with the amorphous phase had the best cycle stability. [Copyright &y& Elsevier]

Abstract: The main purpose of this paper is to investigate the effects of nano-size ZrB2 particles on the microstructure and tensile properties of 2024Al matrix composites. The microstructure and tensile properties of the 2024Al matrix composites reinforced by ZrB2 nano-particles fabricated from 2024Al–K2ZrF6–KBF4 system by direct melt reaction are investigated by XRD, OM, SEM, EDS, TEM and tensile testing. The results reveal that the ZrB2 nano-particles exhibit rectangular and nearly hexagon shape with the size ranging from 30 to 100nm, and the reasonable uniform distribution of ZrB2 nano-particles gives rise to significant grain refinement of 2024Al alloy. Tensile testing results show that the tensile strength and yield stress of the composites increase continuously. However, the elongation of the composites increases almost linearly and declines later as the increasing of ZrB2 content. The fracture morphologies are in accord with corresponding ductility results. What’s more, the strengthening mechanism of ZrB2 nano-particles is established. [Copyright &y& Elsevier]

Objective: To investigate 5 years' experience with fine needle aspiration (FNA) of salivary glands at a single academic center., Study Design: A total of 191 salivary gland FNAs were performed at Louisiana State University Health Science Center from 2003 to 2007, and all were done on major salivary glands except for 1 case., Results: The cytologic diagnoses included 17 malignancies, 6 atypia, 73 neoplasms, 87 negative and 18 nondiagnostic. Eighty-six cases had histologic follow-up (45.0%). There were 5 false negatives: 2 adenoid cystic carcinomas, 1 acinic cell carcinoma, 1 polymorphous low grade adenocarcinoma and 1 metastatic basaloid squamous cell carcinoma. The only false positive was a pleomorphic adenoma misdiagnosed as adenoid cystic carcinoma. Four reactive processes were diagnosed as benign neoplasms, including 2 granulomatous inflammation and 2 chronic sialadenitis. Five benign neoplasms were interpreted as reactive processes, including 2 Warthin's tumors, 2 sebaceous lymphoadenomas and 1 pleomorphic adenoma. The overall accuracy in distinguishing benign from malignant lesions was 79.1%, and the sensitivity for salivary neoplasia was 89.4%., Conclusion: Our results are consistent with the literature that salivary gland FNA has good sensitivity, specificity and accuracy in the diagnosis of salivary neoplasms. FNA can play a significant role in triaging patients with onsite cytologic interpretation and can reduce many unnecessary surgeries.