An investigation has been carried out to compare th e cutting performance and tool life evaluation of high speed steel broach samp les. The comparison has been done between conventional M2 and Anti-Segregation Process...An investigation has been carried out to compare th e cutting performance and tool life evaluation of high speed steel broach samp les. The comparison has been done between conventional M2 and Anti-Segregation Process (ASP) ASP53 and ASP30 high speed steel broach samples. The ASP53 was a development material. The cutting performance was evaluated by measuring the c utting forces and calculating the specific cutting energy, an indicator of cutti ng performance. As the roughness of the machined surface is an important criter ion in the evaluation of performance of a tool, the surface roughness of the workpiece was studied as a function of undeformed chip thickness. The workpiec e material was 150M36 alloy steel used in manufacture of automobile engines. Th e performance tests were conducted at two cutting speeds, which were 0 7 m/min and 10.5 m/min respectively. This allowed a better understanding of the effect of cutting speed on tool performance. The wear tests were performed at a cuttin g speed on 10.5 m/min. The cutting edges of ASP broach samples were finer compared to that of M2. Ther e was no practical difference in the cutting forces and the specific cutting ene rgy while cutting with MS, ASP30 and ASP53 broach samples. The ASP30 and ASP53 tools have a better surface roughness on the machined surface than that of M2 at both cutting speeds. The ASP30 gave 2.25 times the life and an improved surfac e finish compared to M2 steel. The ASP53 gave 1.3 times the life of M2 steel. These results should prove useful to the tool designer and manufacturing enginee r.展开更多
In order to improve the cutting performance in broaching,the lubrication and cleaning effects offered by water-based cutting fluids with green additives need to be studied from the viewpoint of green manufacturing.The...In order to improve the cutting performance in broaching,the lubrication and cleaning effects offered by water-based cutting fluids with green additives need to be studied from the viewpoint of green manufacturing.Therefore,water-based solutions with castor oil,surfactant(linear alkylbenzene sulfonate,LAS),and nanographite were prepared by ultrasonic agitation and sprayed into the zone of broaching via atomization.The performances of the cutting fluids,in terms of the viscosity,specific heat,wetting angle,and droplet size,were evaluated to discuss their effects on the broaching load.Among the fluids,the addition of LAS into oil-in-water(WO-S),where its cutting fluid with 10 wt.%castor oil and 1.5 wt.%surfactant,exhibited the lowest broaching force.With regard to the lubricating and cleaning mechanisms,WO-S has good wettability and permeability,and hence,can lubricate the cutting edge of the tool to decrease the cutting load,cool the cutting edge to keep it sturdy,and clean the surface of the cutting edge to keep it sharp.The results reveal that the simultaneous addition of castor oil and LAS had remarkable effects on the lubrication and cleaning,and resulted in a broaching load reduction of more than 10%compared to commercial cutting fluids.However,the addition of nanographite could not improve the lubrication owing to its agglomeration.展开更多
With increasing environmental concerns,the substitution of mineral oil-based cutting fluid has become an urgent issue.Using vegetable soybean oil as base fluid,nanofluid cutting fluids(NFCFs)were prepared by adding di...With increasing environmental concerns,the substitution of mineral oil-based cutting fluid has become an urgent issue.Using vegetable soybean oil as base fluid,nanofluid cutting fluids(NFCFs)were prepared by adding different weight concentrations of nanographite particles(NGPs),and their penetration and lubrication performances were studied.A novel simulated tool-chip slit with micrometersized geometry was manufactured to evaluate and quantify the penetration rate of the NFCFs by image analysis approach.Moreover,a large number of comparative experiments on the closed-type broaching machine were carried out to compare the performance of the proposed NFCFs and a commercial cutting fluid in terms of cutting force,workpiece surface roughness,and metal chip.It is found that there is an optimal NGP concentration in NFCF for practical cutting applications.When the concentration of NGP is 0.4 wt%,the broaching process lubrication exhibits an ideal mixed lubricate state,resulting in minimal friction resistance,and thus,both the cutting force and chip curling angle reach their corresponding best values.Moreover,the proposed NGP-based vegetable-oil cutting fluid exhibits excellent environmentfriendliness and low-cost consumption in the minimal quantity lubrication(MQL)method;this demonstrates its potential for replacing the traditional broaching cutting fluid.展开更多
This study focuses on the influence of the wave surge force on the assessments of the surf-riding/broaching vulnerability criteria according to the new proposal of the IMO Second Generation Intact Stability Criteria. ...This study focuses on the influence of the wave surge force on the assessments of the surf-riding/broaching vulnerability criteria according to the new proposal of the IMO Second Generation Intact Stability Criteria. A code is developed for the criteria check and the sample ship calculations show that the accuracy of the wave surge force estimation has a significant influence on the assessment result. For further investigation, the wave surge force measurement through a captive model test is made for a purse seiner to validate the numerical model, the effects of the wave steepness and the ship forward speed on the wave surge force responses are also discussed. It is demonstrated that the diffraction effect is important for the correct estimation of the wave surge force. Therefore, it is recommended to include this effect in the assessment procedure.展开更多
文摘An investigation has been carried out to compare th e cutting performance and tool life evaluation of high speed steel broach samp les. The comparison has been done between conventional M2 and Anti-Segregation Process (ASP) ASP53 and ASP30 high speed steel broach samples. The ASP53 was a development material. The cutting performance was evaluated by measuring the c utting forces and calculating the specific cutting energy, an indicator of cutti ng performance. As the roughness of the machined surface is an important criter ion in the evaluation of performance of a tool, the surface roughness of the workpiece was studied as a function of undeformed chip thickness. The workpiec e material was 150M36 alloy steel used in manufacture of automobile engines. Th e performance tests were conducted at two cutting speeds, which were 0 7 m/min and 10.5 m/min respectively. This allowed a better understanding of the effect of cutting speed on tool performance. The wear tests were performed at a cuttin g speed on 10.5 m/min. The cutting edges of ASP broach samples were finer compared to that of M2. Ther e was no practical difference in the cutting forces and the specific cutting ene rgy while cutting with MS, ASP30 and ASP53 broach samples. The ASP30 and ASP53 tools have a better surface roughness on the machined surface than that of M2 at both cutting speeds. The ASP30 gave 2.25 times the life and an improved surfac e finish compared to M2 steel. The ASP53 gave 1.3 times the life of M2 steel. These results should prove useful to the tool designer and manufacturing enginee r.
基金This research is supported by National Natural Science Foundation of China(Grant No.51775153).
文摘In order to improve the cutting performance in broaching,the lubrication and cleaning effects offered by water-based cutting fluids with green additives need to be studied from the viewpoint of green manufacturing.Therefore,water-based solutions with castor oil,surfactant(linear alkylbenzene sulfonate,LAS),and nanographite were prepared by ultrasonic agitation and sprayed into the zone of broaching via atomization.The performances of the cutting fluids,in terms of the viscosity,specific heat,wetting angle,and droplet size,were evaluated to discuss their effects on the broaching load.Among the fluids,the addition of LAS into oil-in-water(WO-S),where its cutting fluid with 10 wt.%castor oil and 1.5 wt.%surfactant,exhibited the lowest broaching force.With regard to the lubricating and cleaning mechanisms,WO-S has good wettability and permeability,and hence,can lubricate the cutting edge of the tool to decrease the cutting load,cool the cutting edge to keep it sturdy,and clean the surface of the cutting edge to keep it sharp.The results reveal that the simultaneous addition of castor oil and LAS had remarkable effects on the lubrication and cleaning,and resulted in a broaching load reduction of more than 10%compared to commercial cutting fluids.However,the addition of nanographite could not improve the lubrication owing to its agglomeration.
基金the National Natural Science Foundation of China(Nos.51709240 and 51579144)the High-Tech Ship Research Project Supported by Ministry of Industry and Information Technology(No.K24352)the Equipment Pre-research Project(No.41407010202)
基金This study is supported by the National Natural Science Foundation of China(Grant Nos.51775153 and 51975171).
文摘With increasing environmental concerns,the substitution of mineral oil-based cutting fluid has become an urgent issue.Using vegetable soybean oil as base fluid,nanofluid cutting fluids(NFCFs)were prepared by adding different weight concentrations of nanographite particles(NGPs),and their penetration and lubrication performances were studied.A novel simulated tool-chip slit with micrometersized geometry was manufactured to evaluate and quantify the penetration rate of the NFCFs by image analysis approach.Moreover,a large number of comparative experiments on the closed-type broaching machine were carried out to compare the performance of the proposed NFCFs and a commercial cutting fluid in terms of cutting force,workpiece surface roughness,and metal chip.It is found that there is an optimal NGP concentration in NFCF for practical cutting applications.When the concentration of NGP is 0.4 wt%,the broaching process lubrication exhibits an ideal mixed lubricate state,resulting in minimal friction resistance,and thus,both the cutting force and chip curling angle reach their corresponding best values.Moreover,the proposed NGP-based vegetable-oil cutting fluid exhibits excellent environmentfriendliness and low-cost consumption in the minimal quantity lubrication(MQL)method;this demonstrates its potential for replacing the traditional broaching cutting fluid.
基金Project supported by the High-Technology Ship Research Project of Ministry of Industry and Information Technology(Grant No.K24352)the National Natural Science Foundation of China(973 Praogram,Grant No.51579144)
文摘This study focuses on the influence of the wave surge force on the assessments of the surf-riding/broaching vulnerability criteria according to the new proposal of the IMO Second Generation Intact Stability Criteria. A code is developed for the criteria check and the sample ship calculations show that the accuracy of the wave surge force estimation has a significant influence on the assessment result. For further investigation, the wave surge force measurement through a captive model test is made for a purse seiner to validate the numerical model, the effects of the wave steepness and the ship forward speed on the wave surge force responses are also discussed. It is demonstrated that the diffraction effect is important for the correct estimation of the wave surge force. Therefore, it is recommended to include this effect in the assessment procedure.
