Pouring and mold temperatures are two important parameters during casting magnesium components. The present study examined their influence on hot tearing susceptibility （HTS） of commercial AZ91D and newly developed ...Pouring and mold temperatures are two important parameters during casting magnesium components. The present study examined their influence on hot tearing susceptibility （HTS） of commercial AZ91D and newly developed Mg-3Nd-0.2Zn-Zr （mass fraction, %; NZ30K） magnesium alloys in gravity permanent mold casting condition. The results indicate that mold temperature shows much more significant influence on the HTS of both alloys than pouring temperature whose influence only can be distinguished at low mold temperature （341 K for AZ91D alloy and 423 K for NZ30K alloy）. Hot tearing susceptibility prediction model concerning feeding parameters, grain size and solidification range, is more suitable to estimate the HTS of different magnesium alloys than the model only concerning feeding parameters. In order to achieve better hot tearing resistance, the ranges of pouring and mold temperatures are suggested to be 961-991 K and≥641 K for AZ91D alloy, 1003-1033 K and≥623 K for NZ30K alloy, respectively.展开更多
A novel, Nb- and Si-rich and Be-free Ni-based alloy was cast by two methods of investment casting and continuouscasting to study the microstructure evolution during solidification and its mechanical properties. The so...A novel, Nb- and Si-rich and Be-free Ni-based alloy was cast by two methods of investment casting and continuouscasting to study the microstructure evolution during solidification and its mechanical properties. The solidification of the alloy startedwith the primary crystallization of FCC-γ, followed by a binary eutectic reaction, with the formation of a heterogeneous constituent：FCC-γ＋G-phase, which replaced the low-melting eutectic （FCC-γ＋NiBe） in the Be-bearing alloys. AlNi6Si3 and γ′ formed during theterminal stages of solidification by investment casting, while the formation of AlNi6Si3 was suppressed by continuous casting. TheScheil solidification model agreed very well with the experimental results.展开更多
This paper concentrates on the research of plaster-bonded moulding matertal with coal mine waste as its major filler and its process. Having made a careful investigation of various factorsaffecting properties of the m...This paper concentrates on the research of plaster-bonded moulding matertal with coal mine waste as its major filler and its process. Having made a careful investigation of various factorsaffecting properties of the moulding material, the authors optimize several new formulations of thismaterial and the prarees which are inexpensive, convenient in application, precise in bokling sizoof moulds.展开更多
基金Project (2009AA033501) supported by the High-tech Research and Development Program of China
文摘Pouring and mold temperatures are two important parameters during casting magnesium components. The present study examined their influence on hot tearing susceptibility （HTS） of commercial AZ91D and newly developed Mg-3Nd-0.2Zn-Zr （mass fraction, %; NZ30K） magnesium alloys in gravity permanent mold casting condition. The results indicate that mold temperature shows much more significant influence on the HTS of both alloys than pouring temperature whose influence only can be distinguished at low mold temperature （341 K for AZ91D alloy and 423 K for NZ30K alloy）. Hot tearing susceptibility prediction model concerning feeding parameters, grain size and solidification range, is more suitable to estimate the HTS of different magnesium alloys than the model only concerning feeding parameters. In order to achieve better hot tearing resistance, the ranges of pouring and mold temperatures are suggested to be 961-991 K and≥641 K for AZ91D alloy, 1003-1033 K and≥623 K for NZ30K alloy, respectively.
基金supported by the ARRS under the framework of the Slovenian-Brazilian Bilateral Project BI-BR/12-14-003funding from the European Union Seventh Framework Programme under Grant Agreement 312483-ESTEEM2(Integrated Infrastructure InitiativeI3)
文摘A novel, Nb- and Si-rich and Be-free Ni-based alloy was cast by two methods of investment casting and continuouscasting to study the microstructure evolution during solidification and its mechanical properties. The solidification of the alloy startedwith the primary crystallization of FCC-γ, followed by a binary eutectic reaction, with the formation of a heterogeneous constituent：FCC-γ＋G-phase, which replaced the low-melting eutectic （FCC-γ＋NiBe） in the Be-bearing alloys. AlNi6Si3 and γ′ formed during theterminal stages of solidification by investment casting, while the formation of AlNi6Si3 was suppressed by continuous casting. TheScheil solidification model agreed very well with the experimental results.
文摘This paper concentrates on the research of plaster-bonded moulding matertal with coal mine waste as its major filler and its process. Having made a careful investigation of various factorsaffecting properties of the moulding material, the authors optimize several new formulations of thismaterial and the prarees which are inexpensive, convenient in application, precise in bokling sizoof moulds.
