摘要:The non-harmonious character of structure of La modification in Al-Si eutectic alloys has been systematically studied in this paper by optical and reading microscopes, SEM, electron microproble, etc. in cylinder samples. It is found that La modification is of non-harmonious character. This character depends on the freezing rate and equilibrium distribution coefficient of lanthanum.
摘要:In order to fulfil the high-speed numerical simulation of casting solidification processes, the Dynamic Boundary Condition Calculation is proposed first time. On the basis of the Similitude Theory in the heat transfer, the authors put forward the Biot Criterion Amendment Formulae. The experiments show that comparing with the traditional simulation methods, it is able to have the used computer storage and time cut down by 6080%, and the relative error of the calculated solidification time is only 3.69%.
摘要:The alloy with simple melting process, good castability and wearability, high strength, low cost is a low melting point nonferrous alloy which can be forged and plated, and is an ideal material which can be substituted for some cupro-base alloy to manufacture wear-resisting and structural parts.
摘要:The relatiop between change of sodium oxide in ceramic shell mould and its mechanical properties at high temperature were studied by using chemical analysis, X-ray diffraction analysis, polarization microscope and DTA, etc.,The reaction mechanism of high temperature and production control of sodium oxide were also discussed.
摘要:This paper analyses the optimigation compositions of hypereutectic Al-Si alloys for pistons,according to the specific property of hypsreutectic Al-Si alloys. The compound salt modifier of development and production with phospho-sulphur can be used to batch process. This kind of modifier can refine not only the crystals of primary silicon but also the eutectic sillicon, and the effective period can last 3 hours. The properties of the alloys have surpassed the requirement of the state standard "GB1148-82". Now, it has been used to batch process.
摘要:The effect of cement, content,moisture content,addition of speed-hardening agent and foamine agent ou the properties of fluid nobake is studed. The fluid nobake sand is suitable for full-mould casting process.