To determine mirror surface finishing conditions and efficient and economical superfinishing conditions for pure titanium and titanium alloys, an abrasive film is used when superfinishing is performed under varying co...To determine mirror surface finishing conditions and efficient and economical superfinishing conditions for pure titanium and titanium alloys, an abrasive film is used when superfinishing is performed under varying conditions. These conditions include the workpiece rotation speed, the oscillation speed, the contact pressure of the roller, the hardness of the roller, and the type of abrasive film. The superfinishing device is applied to polishing a thin and long cylindrical bar. A micro-finishing film and a lapping film were used as abrasive films. A1203 grains or SiC grains were used as abrasives. The surface roughness of a polished workpiece was measured using a stylus-type surface-roughness measuring instrument. As a result, the conditions to improve the polishing surface efficiently include high values for the workpiece rotation speed, oscillation speed and contact pressure. The roller hardness has no effect on the efficient polishing conditions. The mirror finish of a surface can be created using lapping film of 3 μm with Al2O3 grains after polishing to a steady surface roughness under the efficient polishing conditions.展开更多
Harmonic suppression, non-periodic and non-closing in straightness profile error that will bring about harmonic component distortion in measurement result are analyzed. The countermeasure-a novel accurate two-probe me...Harmonic suppression, non-periodic and non-closing in straightness profile error that will bring about harmonic component distortion in measurement result are analyzed. The countermeasure-a novel accurate two-probe method in time domain is put forward to measure straight-going component motion error in machine tools based on the frequency domain 3-point method after symmetrical continuation of probes' primitive signal. Both straight-going component motion error in machine tools and the profile error in workpiece that is manufactured on this machine can be measured at the same time. The information is available to diagnose the fault origin of machine tools. The analysis result is proved to be correct by the experiment.展开更多
The machining accuracy of workpiece is influenced by its orientation deviation, which is caused by the fixture-workpiece error. Based on the spatial coordinate theory, the orientation deviation of workpiece is measure...The machining accuracy of workpiece is influenced by its orientation deviation, which is caused by the fixture-workpiece error. Based on the spatial coordinate theory, the orientation deviation of workpiece is measured by using an on-machine verification system, which can take into account the errors resulting from fixture manufacturing, installation and adjustment, location and clamping of workpiece. According to the least square method, the model of orientation deviation is built to determine the relationship between the theoretical and actual coordinate systems. The influence of orientation deviation on machining accuracy is quantified, and it is shown that the orientation deviation only affects the dimensional precision and position precision, rather than shape precision. In the experiment, the compensation processing of realtime errors was conducted, and the perpendicularity and inclination errors of the tetragonal part were reduced by 38.46% and 47.06%, respectively.展开更多
Starch ofavocado seeds can be used as an alternative source of starch because it contains 80.1% starch. Natural starch can be made into a modified starch, for example dextrin. Dextrin can be made by using acid or enzy...Starch ofavocado seeds can be used as an alternative source of starch because it contains 80.1% starch. Natural starch can be made into a modified starch, for example dextrin. Dextrin can be made by using acid or enzyme hydrolysis. The purposes of this research were determine the concentration of hydrochloric acid （HCl）, the temperature and heating timein the optimum process of hydrolysis of starch into dextrin and to determine the quality of the resulting product dextrin terms of Indonesian National Standard 01-2593-1992. The methode was used in this research is hydrolisis with hydrochloric acid （HCl）. The results processing into starch avocado seed yield is 23.15%. HCl concentration, temperature and heating time significantly affect the value of dextrose equivalent （DE）, viscosity and part soluble in cold water. There is interaction between HCl concentration, temperature and heating time on the value of DE, viscosity and part soluble in cold water. Optimum conditions of process was obtained at a concentration of 0.15 N HCl, 30 minutes heating time and heating temperature of 90 ℃. Dextrose equivalent （DE） value is 19.61%. The value of solubility in cold water is 90.19%. Viscosity value is 1.61 ° E. Dextrin is not accordance with the standards of quality parameters Indonesian National Standard 01-2593-1992. Dextrin produced should be applied to non-food industry.展开更多
基金work supported by the Second Stage of Brain Korea 21 Projects of Korea
文摘To determine mirror surface finishing conditions and efficient and economical superfinishing conditions for pure titanium and titanium alloys, an abrasive film is used when superfinishing is performed under varying conditions. These conditions include the workpiece rotation speed, the oscillation speed, the contact pressure of the roller, the hardness of the roller, and the type of abrasive film. The superfinishing device is applied to polishing a thin and long cylindrical bar. A micro-finishing film and a lapping film were used as abrasive films. A1203 grains or SiC grains were used as abrasives. The surface roughness of a polished workpiece was measured using a stylus-type surface-roughness measuring instrument. As a result, the conditions to improve the polishing surface efficiently include high values for the workpiece rotation speed, oscillation speed and contact pressure. The roller hardness has no effect on the efficient polishing conditions. The mirror finish of a surface can be created using lapping film of 3 μm with Al2O3 grains after polishing to a steady surface roughness under the efficient polishing conditions.
基金National Nature Science Foundation of China.No.50075056
文摘Harmonic suppression, non-periodic and non-closing in straightness profile error that will bring about harmonic component distortion in measurement result are analyzed. The countermeasure-a novel accurate two-probe method in time domain is put forward to measure straight-going component motion error in machine tools based on the frequency domain 3-point method after symmetrical continuation of probes' primitive signal. Both straight-going component motion error in machine tools and the profile error in workpiece that is manufactured on this machine can be measured at the same time. The information is available to diagnose the fault origin of machine tools. The analysis result is proved to be correct by the experiment.
基金Supported by National Natural Science Foundation of China (No.50975200)
文摘The machining accuracy of workpiece is influenced by its orientation deviation, which is caused by the fixture-workpiece error. Based on the spatial coordinate theory, the orientation deviation of workpiece is measured by using an on-machine verification system, which can take into account the errors resulting from fixture manufacturing, installation and adjustment, location and clamping of workpiece. According to the least square method, the model of orientation deviation is built to determine the relationship between the theoretical and actual coordinate systems. The influence of orientation deviation on machining accuracy is quantified, and it is shown that the orientation deviation only affects the dimensional precision and position precision, rather than shape precision. In the experiment, the compensation processing of realtime errors was conducted, and the perpendicularity and inclination errors of the tetragonal part were reduced by 38.46% and 47.06%, respectively.
文摘Starch ofavocado seeds can be used as an alternative source of starch because it contains 80.1% starch. Natural starch can be made into a modified starch, for example dextrin. Dextrin can be made by using acid or enzyme hydrolysis. The purposes of this research were determine the concentration of hydrochloric acid （HCl）, the temperature and heating timein the optimum process of hydrolysis of starch into dextrin and to determine the quality of the resulting product dextrin terms of Indonesian National Standard 01-2593-1992. The methode was used in this research is hydrolisis with hydrochloric acid （HCl）. The results processing into starch avocado seed yield is 23.15%. HCl concentration, temperature and heating time significantly affect the value of dextrose equivalent （DE）, viscosity and part soluble in cold water. There is interaction between HCl concentration, temperature and heating time on the value of DE, viscosity and part soluble in cold water. Optimum conditions of process was obtained at a concentration of 0.15 N HCl, 30 minutes heating time and heating temperature of 90 ℃. Dextrose equivalent （DE） value is 19.61%. The value of solubility in cold water is 90.19%. Viscosity value is 1.61 ° E. Dextrin is not accordance with the standards of quality parameters Indonesian National Standard 01-2593-1992. Dextrin produced should be applied to non-food industry.
