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In this paper, alloys with compositions of Mgx(MnAlZnCu)100-x (x: atomic percentage; x=20, 33, 43, 45.6 and 50 respectively) were designed by using the strategy of equiatomic ratio and high entropy of mixing. Microstructure and mechanical properties of the new high entropy alloy were studied. The alloys were prepared by induction melting and then were cast in a copper mold in air. The alloy samples were examined by microhardness tester, XRD, SEM, thermal analyzer and testing machine for material strength. Alloys were composed mainly of h.c.p phase and Al-Mn icosahedral quasicrystal phases. The alloys exhibited moderate densities which were from 4.29g•cm-3 to 2.20g•cm-3, high hardness (429HV-178HV) and high compression strength (500MPa-400MPa) at room temperature. The extensibility was increased with Mg from 20at% (atomic percentage) to 50at%.

In this paper, alloy with composition of MgMnAlZnCu was designed by using the strategy of equiatomic ratio and high entropy of mixing. The microstructure and mechanical parameters of the new high entropy alloy cooling in three conditions were studied. The alloy was prepared by induction melting and then it was cast in copper molds in air, water and salt water respectively. The microstructure and properties of alloy samples were examined by microhardness tester, XRD, TEM, SEM and testing machine for material strength. The results showed that the alloy was composed mainly of h.c.p and Al-Mn quasicrystal phases. The alloy exhibit high hardness (431HV-467HV) and high compression strength (428MPa-450MPa) at room temperature. The alloy was fragile and the strains were from 3.29% to 5.53%.

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The accuracy of machine tools is significantly affected by the geometric defect and thermal deformation of the mechanical components. This paper intends to provide a comprehensive compensation method for the integrated geometric and thermal errors of machine tools. Firstly, a synthesized volumetric model is established with homogeneous transformation matrix method, considering both the geometric and thermal effects. Then, in order to improve the modeling accuracy and efficiency of the geometric error components, an automatic modeling algorithm is proposed with the Chebyshev polynomial-based orthogonal least squares regression. Also, to improve the robustness of the thermal error models for the feed axes and the spindle system, the thermal effects caused by external ambient variation and internal heat sources are identified and modeled separately. Finally, an intelligent virtual compensation system is developed for machine tools based on the function of external machine original coordinate shift and fast Ethernet data interaction technique, and compensation tests on a vertical machining center showed that the position accuracy of the machine tool could be significantly improved after compensation.

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