During the process of deep?hole gun drilling,the shape of the chip is a significant factor affecting the final quality.The relationship between chip forming mechanism and process parameters has always been a complicat...During the process of deep?hole gun drilling,the shape of the chip is a significant factor affecting the final quality.The relationship between chip forming mechanism and process parameters has always been a complicated problem in deep?hole drilling.This paper investigates Ti6Al4V titanium alloy to address this issue.First,the four processes and influencing factors of forming spiral chips are analyzed theoretically.Second,the fracture mechanism of chips in drilling Ti6Al4V titanium alloy is analyzed by scanning electron microscopy.Finally,the influences of cutting speed,feed rate and coolant oil pressure on chip shape are analyzed through drilling experiments and fluid simulation.The relationship between chip compression ratio and surface roughness is obtained through chip thickness measurement.This research can provide a guide for optimizing parameters of deep?hole gun drilling on Ti6Al4V titanium alloy.展开更多
In this paper,the rapid and integrated manufacture method of 3 D printing gun drill is put forward.The 3 D printing process test of the composites gun drill composed of medium carbon steel drill shank,low alloy steel ...In this paper,the rapid and integrated manufacture method of 3 D printing gun drill is put forward.The 3 D printing process test of the composites gun drill composed of medium carbon steel drill shank,low alloy steel drill pipe and tungsten cobalt hard alloy drill bit is conducted.Microstructure and morphology of the composites gun drill interface between low alloy steel and tungsten cobalt hard alloy is analyzed using SEM.Element distribution and Phase composition of the interface between low alloy steel and tungsten cobalt hard alloy were tested and analyzed by EDS and XRD respectively.The oxidation resistance,micro hardness and corrosion resistance of the interface between low alloy steel and tungsten cobalt hard alloy were analyzed.The results show that the interface performance of 3 D printing composite gun drill is better than that of the welding gun drill.The rapid and integrated 3 D printing method is feasible for gun drill manufacture.展开更多
Chip shape is one of the important factors that affect the processing quality of the deep hole.The flow field of 17 mm standard gun-drill is simulated by taking the coolant pressure as a single factor variable,and the...Chip shape is one of the important factors that affect the processing quality of the deep hole.The flow field of 17 mm standard gun-drill is simulated by taking the coolant pressure as a single factor variable,and the influence of coolant pressure on chip forming is discussed by combining with experiments in this paper.The results show that at the initial stage of chip forming,the flow of cutting fluid will intensify the lateral crimp of chips,and then affect the crimp radius of the chip and the number of turns of the crimp screw.The lateral crimp degree increases first and then decreases with the increase of coolant pressure,and the crimp degree is the smallest at 3 MPa.In addition,during the chip removal process,the stream shrinking in the flow field is the main influencing factor that drive and force the chip to break again,and their influence on the chip removal and chip breaking is proportional to the coolant pressure.展开更多
基金supported in part by the National Natural Science Foundation of China (No. 51505409)the Jiangsu Postgraduate Research and Practice Innovation Program (SJCX18_0884).
文摘During the process of deep?hole gun drilling,the shape of the chip is a significant factor affecting the final quality.The relationship between chip forming mechanism and process parameters has always been a complicated problem in deep?hole drilling.This paper investigates Ti6Al4V titanium alloy to address this issue.First,the four processes and influencing factors of forming spiral chips are analyzed theoretically.Second,the fracture mechanism of chips in drilling Ti6Al4V titanium alloy is analyzed by scanning electron microscopy.Finally,the influences of cutting speed,feed rate and coolant oil pressure on chip shape are analyzed through drilling experiments and fluid simulation.The relationship between chip compression ratio and surface roughness is obtained through chip thickness measurement.This research can provide a guide for optimizing parameters of deep?hole gun drilling on Ti6Al4V titanium alloy.
基金supported by Key Research and Development(R&D)Projects of Shanxi Province(Grant No.201903D121054)supported by Scientific and Technologial Innovation Programs of Higher Education Institutions in Shanxi(Grant No.2019L0621)。
文摘In this paper,the rapid and integrated manufacture method of 3 D printing gun drill is put forward.The 3 D printing process test of the composites gun drill composed of medium carbon steel drill shank,low alloy steel drill pipe and tungsten cobalt hard alloy drill bit is conducted.Microstructure and morphology of the composites gun drill interface between low alloy steel and tungsten cobalt hard alloy is analyzed using SEM.Element distribution and Phase composition of the interface between low alloy steel and tungsten cobalt hard alloy were tested and analyzed by EDS and XRD respectively.The oxidation resistance,micro hardness and corrosion resistance of the interface between low alloy steel and tungsten cobalt hard alloy were analyzed.The results show that the interface performance of 3 D printing composite gun drill is better than that of the welding gun drill.The rapid and integrated 3 D printing method is feasible for gun drill manufacture.
基金supported in part by the National Natural Science Foundation of China (No. 51505409)the Six Talent Peak Project in Jiangsu Province (No. GDZB-080)the Natural Science Research in Jiangsu Province(No.17KJB460008)。
文摘Chip shape is one of the important factors that affect the processing quality of the deep hole.The flow field of 17 mm standard gun-drill is simulated by taking the coolant pressure as a single factor variable,and the influence of coolant pressure on chip forming is discussed by combining with experiments in this paper.The results show that at the initial stage of chip forming,the flow of cutting fluid will intensify the lateral crimp of chips,and then affect the crimp radius of the chip and the number of turns of the crimp screw.The lateral crimp degree increases first and then decreases with the increase of coolant pressure,and the crimp degree is the smallest at 3 MPa.In addition,during the chip removal process,the stream shrinking in the flow field is the main influencing factor that drive and force the chip to break again,and their influence on the chip removal and chip breaking is proportional to the coolant pressure.
