This article presents a mathematical model of helical end-milling forces through experimental identification of the cutting coefficients and analyzes the changes of comer-milling forces under different conditions. In ...This article presents a mathematical model of helical end-milling forces through experimental identification of the cutting coefficients and analyzes the changes of comer-milling forces under different conditions. In allusion to the corner-milling process, the relationship between working parameters and the comer coordinates is investigated by way of combination of tool tracing and cutting geometrodynamics. The milling parameters are optimized by changing the coordinates of tool center and working parameters without altering curing forces. By applying the optimized parameters to milling practice, a comparison is made to show the improved product quality. Based on these optimized parameters, a finite element method （FEM） program is used to compute deformation values of a workpiece＇s comer, which evidences few effects that optimized parameters can exert on the comer deformation.展开更多
A An analytical method using high resolution inductively coupled plasma mass spectrometry （HR-ICP-MS） for rapid simultaneous determination of 24 elements （Be, Mg, A1, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Ge, As, Se, ...A An analytical method using high resolution inductively coupled plasma mass spectrometry （HR-ICP-MS） for rapid simultaneous determination of 24 elements （Be, Mg, A1, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Ge, As, Se, Mo, Ag, Cd, Sn Sb, Ba, Pt, Au, and Pb） in high purity cobalt was described. Sample digestions were performed in closed microwave vessels using HNO3 and HCI. The matrix effects because of the presence of excess HCI and Co were evaluated. The usefulness of high mass resolution for overcoming some spectral interference was demonstrated. The optimum conditions for the determination were tested and discussed. The standard addition method was employed for quantitative analysis. The detection limits were 0.016-1.50 ].tg·g^-1, the recovery ratios were 92.2%-111.2%, and the RSD was less than 3.6%. The method was accurate, quick, and convenient. It was applied to the determination of trace impurities in high purity cobalt with satisfactory results.展开更多
基金National Defense Basic Research Program (D0620060433)
文摘This article presents a mathematical model of helical end-milling forces through experimental identification of the cutting coefficients and analyzes the changes of comer-milling forces under different conditions. In allusion to the corner-milling process, the relationship between working parameters and the comer coordinates is investigated by way of combination of tool tracing and cutting geometrodynamics. The milling parameters are optimized by changing the coordinates of tool center and working parameters without altering curing forces. By applying the optimized parameters to milling practice, a comparison is made to show the improved product quality. Based on these optimized parameters, a finite element method （FEM） program is used to compute deformation values of a workpiece＇s comer, which evidences few effects that optimized parameters can exert on the comer deformation.
基金the Natural Science Foundation of Hunan Province, China (No. 05JJ40017).
文摘A An analytical method using high resolution inductively coupled plasma mass spectrometry （HR-ICP-MS） for rapid simultaneous determination of 24 elements （Be, Mg, A1, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Ge, As, Se, Mo, Ag, Cd, Sn Sb, Ba, Pt, Au, and Pb） in high purity cobalt was described. Sample digestions were performed in closed microwave vessels using HNO3 and HCI. The matrix effects because of the presence of excess HCI and Co were evaluated. The usefulness of high mass resolution for overcoming some spectral interference was demonstrated. The optimum conditions for the determination were tested and discussed. The standard addition method was employed for quantitative analysis. The detection limits were 0.016-1.50 ].tg·g^-1, the recovery ratios were 92.2%-111.2%, and the RSD was less than 3.6%. The method was accurate, quick, and convenient. It was applied to the determination of trace impurities in high purity cobalt with satisfactory results.
