材料期刊网

WIDE-BAND LASER CLADDING: WEAR AND CORROSION RESISTANCE OF A Ni-BASED ALLOY

Q. Y Pan , WD. Huang , YM. Li , X. Lin , YH. Zhou and X.C. Yan( State Key Lab. of Solidification Processing , Northwestern Polytechnical University , Xi'an 710072 , China ( Laser Processing Center , Tianjin College of Textile Technology , Tianjin 300160 , China )

金属学报(英文版)

A novel wide-band laser cladding system, with high rate of cladding, has been developed in the present work. The system mainly consisted of a 5kW CO2 laser, an automatic Fowder feeder and a wide-band scanning rotative polygon mirmr which can produce a linear or rectangular focused laser beam. Using this system, a Ni-Cr-Si-B alloy powder was cladded on the sudece of tgpe 321 austenitic stainless steel in onder to improve its wear and cormsion resistance. The pitting cormsion, high temperuture oxidation and wear tests were conducted in onder to evaluate the propertles of the laser cladded layer. The results demonstrated that the cladded layer can significantly improtte the adhesive wear and pitting cormsion resistance of the substmte. Moreover,the cladded layer exhibited good oxidafion resistance, which is almost the same as that of GMR-235D N-based superalloy.

关键词: austenitic stainless steel , null , null , null

Titanium technology in the USA - an overview

D.Eylon , S.R.Seagle

材料科学技术（英文）

The state of Ti research, development and industry is reviewed in this article. The fifty-year anniversary of Ti technology commercialization in the USA provides an opportunity for a historical perspective. Incorporation of "information-age" tools into alloy development, processing, and production invigorates the technology. Consolidation, diversification and globalization have been transforming the Ti industry in the recent years.

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Development and application of universal formability technology

Yanwu Xu

材料科学技术（英文）

Using mathematical plasticity theories, universal formability (UF) technology has been developed and applied in the automotive stamping engineering and production. As a formability analysis tool, this technology is the major methodology for the development of stamping expert system (solution provider) for (a) product design and feasibility analysis, (b) material automatic selection using nomograms, (c) draw die design using pre-models, and (d) UF and robustness analysis of die performance in finite element analysis (FEA) environment.

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Residual Stresses in Coating Technology

G.Montay , A.Cherouat , A.Nussair , J.Lu

材料科学技术（英文）

Residual stress in coatings is the result of individual particle stress. Their effects may be either beneficial or detrimental, depending upon the magnitude, sign and distribution of the stresses with respect to the external load. Tensile stress which exceeds the elastic limit causes cracking in surface coatings or at the interface between the substrate and the coat. Compressive stress, in general, has a beneficial effect on the fatigue life, crack propagation, coating adhesion and on the durability of the top coat during service. Compressive residual stresses can increase the number of cycles before crack initiation begins through a mean stress effect. Temperature gradients which occur during solidification and subsequent cooling are the principal mode of internal stresses generation. Some parameters influence the residual stress field of both the coating and the substrate. Substrate nature, spraying temperature, thickness of the coat layer, substrate preparation (grit blasting conditions), and velocity of the splats are in the relation with the quality of the coating. In this work, we will describe the role playing by the ceramics coating elaboration on the residual stress gradient in depth of the component. The incremental hole drilling technique has been developed to determine the residual stress gradient in depth of the coat and substrate which must be used with particularly conditions. This new technology has been employed on zirconia, alumina and tungsten carbide plasma sprayed coating.

关键词: Coating , null , null , null

Recent Advances of Laser Coating Technology in China

LIANG Yong LI Ruiguo Institute of Metal Research , Academia Sinica , Shenyang 110015 , ChinaInstitute of Corrosion and Protection of Metals , Aademia Sinica , Shenyang , 110015 , China

材料科学技术（英文）

Recent advances in laser coating technology including laser cladding,laser surface alloying and laser vapour deposition in China are reviewed in this paper.

关键词: laser , null , null , null , null

INTRODUCTION TO NEW TECHNOLOGY AND EQUIPMENTS IN PINGGUO ALUMINA REFINERY

S.J. Yang , G. Y. Gan and L.Z. Wang (Pingguo Aluminum Company , Guangxi 531400 , China)

金属学报(英文版)

The new technology and equipments used in alumina refinery in PINGGUO ALUMINUM COMPANY were introduced. Problems encountered during early period of its operation and improvements to the process and equipments were discussed. Current opemtion situation and pedect technical and economical figures were also introduced.

关键词: alumina , null , null , null

Microencapsulation technology for thiourea corrosion inhibitor

Journal of Solid State Electrochemistry

The microencapsulation technology was brought in to solidify corrosion inhibitor in order to prolong the releasing time of it. In this work, thiourea (H(2)NCSNH(2)) was used as a corrosion inhibitor and microcapsuled using glutin and polyvinyl alcohol (PVA), respectively, as protective agent. The re-sealing process was used as a way to prolong the releasing time of the H(2)NCSNH(2) encapsulated in microcapsules. It was found that the H(2)NCSNH(2) microcapsule corrosion inhibitor using PVA as a protective agent had a better releasing time. The releasing times of the H(2)NCSNH(2) microcapsule corrosion inhibitors were prolonged from 18 to 48 h by re-sealing process and using PVA as a protective agent. Both the use of PVA as a protective agent and the application of the re-sealing process decreased the encapsulation efficiency of the H(2)NCSNH(2). The performance parameters on protecting Q235 carbon steel from corrosion in 0.1-M H(2)SO(4) solution were evaluated by polarization curve and electrochemical impedance spectra methods. The results showed that the H(2)NCSNH(2) released into the solution from microcapsules could well protect Q235 carbon steel from corrosion and the corrosion-inhibiting mechanisms of it were the same as that of H(2)NCSNH(2).

关键词: Microencapsulation technology;Corrosion;UV spectrophotometric method;Electrochemical impedance spectra;Polarization curve;carbon-steel;3-percent nacl;mild-steel;in-vitro;release;encapsulation;acid;microparticles;microcapsules;derivatives

A novel technology for preparation of high performance fiber by radio frequency heating CVD

材料科学技术（英文）

In this paper, radio frequency (r.f.) heating CVD technology for preparation of high performance fiber has been introduced. SiC, B fibers have been produced by this technology.

关键词:

A novel technology for preparation of high performance fiber by radio frequency heating CVD

Nanlin SHI , Kun LUO , Yapei ZU , Yading DUAN

材料科学技术（英文）

In this paper, radio frequency (r.f.) heating CVD technology for preparation of high performance fiber has been introduced. SiC, B fibers have been produced by this technology.

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THE EVOLUTION OF TECHNOLOGY DEVELOPMENT AT GE CORPORATE R & D

T.B.Cox(GE Corporate Research & Development , Niskayuna , NY 12309 , USA Manuscript received 26 August 1996)

金属学报(英文版)

A brief review of the nearly 100 year history of Corporate Researeh and Development at GE is presented. Observations on the changing nature and relevance of industrial research are discussed. Examples of current technology projects for aircraft engine materials are reviewed. Emphasis of these projects is placed on high performance,low cost and high quality.

关键词: :spray forming , null , null