A pilot wire drawing machine as well as wire end-pointing roller was developed. Using these machines, a wire drawing test for four different coating materials and two different lubricants was performed as the reductio...A pilot wire drawing machine as well as wire end-pointing roller was developed. Using these machines, a wire drawing test for four different coating materials and two different lubricants was performed as the reduction ratio increased from 10% to 30%. Materials used for a substrate in this study are plain carbon steel （AIS11045） and ultra low carbon bainite steel. To compute the friction coefficient between the coating layer of wire and the surface of die lbr a specific lubricant, a series of finite element analyses were carried out. SEM observations were also conducted to investigate the surface defects of wire deformed. Results show that the behavior of drawing force varies with the lubricant-type at the initial stage of drawing. The powder-typed lubricant with a large particle causes the retardation of lull lubrication on the entire contact surface and the local delamination of coating layer on the wire surface. As the flow stress of a substrate increases, the delamination becomes severe.展开更多
Introduccion: Pneumotonometers are handy equipments for testing intraocular pressures (IOP) both for physicians and patients and doesn’t transmit infectious illnesses, but are also known to have a less stabl...Introduccion: Pneumotonometers are handy equipments for testing intraocular pressures (IOP) both for physicians and patients and doesn’t transmit infectious illnesses, but are also known to have a less stable estimation of the IOP values comparing to the conventional Goldmann applanation tonometer. Objective: In this study, we try to define the range of展开更多
基金supported by research funds from Dong-A University, Korea
文摘A pilot wire drawing machine as well as wire end-pointing roller was developed. Using these machines, a wire drawing test for four different coating materials and two different lubricants was performed as the reduction ratio increased from 10% to 30%. Materials used for a substrate in this study are plain carbon steel （AIS11045） and ultra low carbon bainite steel. To compute the friction coefficient between the coating layer of wire and the surface of die lbr a specific lubricant, a series of finite element analyses were carried out. SEM observations were also conducted to investigate the surface defects of wire deformed. Results show that the behavior of drawing force varies with the lubricant-type at the initial stage of drawing. The powder-typed lubricant with a large particle causes the retardation of lull lubrication on the entire contact surface and the local delamination of coating layer on the wire surface. As the flow stress of a substrate increases, the delamination becomes severe.
文摘Introduccion: Pneumotonometers are handy equipments for testing intraocular pressures (IOP) both for physicians and patients and doesn’t transmit infectious illnesses, but are also known to have a less stable estimation of the IOP values comparing to the conventional Goldmann applanation tonometer. Objective: In this study, we try to define the range of
