A large amount of cutting heat is produced during the heavy cutting process,and insert life is restricted by the effect of thermal load.The thermal load experiment of cemented carbide SCS,WF and YT15 is carried out,an...A large amount of cutting heat is produced during the heavy cutting process,and insert life is restricted by the effect of thermal load.The thermal load experiment of cemented carbide SCS,WF and YT15 is carried out,and the results show that the bending strength and fracture toughness of cemented carbide material decrease obviously under cyclic thermal load,while in the cooling process,the material mechanical property changes worse suddenly.The high-temperature mechanical property of SCS is the most stable,and that of YT15 is the worst.Further,a relation model among cutting temperature,cutting parameters and insert life is established.Finally,the measures to improve heavy cemented carbide inserts life are summarized from the aspects of cutting parameters selection,insert optimization design and TiCN,Al2O3,TiN complex insert coating.The research results are expected to provide support and reference for heavy cutting technology and insert technology.展开更多
<span style="font-family:Verdana;">A metal matrix composite constitutes a continuous metallic matrix and a </span><span style="font-family:Verdana;">discontinuous phase known as r...<span style="font-family:Verdana;">A metal matrix composite constitutes a continuous metallic matrix and a </span><span style="font-family:Verdana;">discontinuous phase known as reinforcement. The hybrid metal matrix composites</span><span style="font-family:Verdana;"> (Hmmcs) have been used to manufacture drive shafts, disc brake rotors, brake drums, connecting rods pistons, engine block cylinder liners for automotive and rail vehicle applications. The Hmmcs castings of diameter 120 mm and length 300 mm were prepared through sand mould technique following stir casting methodology. The cast components further subjected to evaluation of physical properties and machining tests using two grades of coated inserts and PCD inserts. The experiments were carried out following ISO 3685 standards. The coating thickness of the TiN coated and TiAlN coated inserts were measured using Kalo testing method</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">;</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> the results of the test show that the interface of the substrate and coating was free from the porosity, and the coating thickness of TiN coating was 4.84 microns and TiAlN coating was measured 4.6 microns. The results of the experiments show that performance of the PCD insert was better than coated inserts at 0.1 mm/rev feed</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">;</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> however at 0.2 mm/revolution feed PCD insert failed by micro chipping of cutting edge while machining Hmmcs. When TiAlN coated inserts were used to machine Hmmcs the coated inserts failed by gradual wear and BUE formation.展开更多
The requirements of high quality machined surface as well as demand of enhanced contact time of cutting tools drive towards adopting multilayer coated carbide inserts. The industry requires higher productivity, hence ...The requirements of high quality machined surface as well as demand of enhanced contact time of cutting tools drive towards adopting multilayer coated carbide inserts. The industry requires higher productivity, hence higher machining parameters need to be used in order to meet the industry requirements. The alloy steel material used to fabricate machine parts consists of alloying elements like nickel, chromium and molybdenum difficult to machine, since the cutting tool fails by high tool wear, if we use uncoated carbide inserts to machine alloy steels. Hence in the present research work it is intended to use tungsten carbide inserts coated with different coatings for the experiments. The turning experiments were carried out using different grades of uncoated and coated carbide inserts of identical tool signature. The cutting speed selected for the experiments was 100 to 500 m/min in steps of 100 m/min, and the feed per revolution was 0.1 mm to 0.4 mm in step of 0.1 mm. The experimentation was carried out following ISO3685 standards. The results of the experiments revealed that the surface roughness measured was the least at cutting speed 500 m/min and feed per revolution of 0.1 mm, however the chip breaking found better when the feed used was greater than 0.2 mm/revolution.展开更多
目的探讨叙事护理在肿瘤患者经外周静脉置入中心静脉导管(peripherally inserted central catheter,PICC)留置期间延续性护理中的应用效果。方法选取2023年12月—2024年5月在厦门大学附属第一医院行PICC维护的100例肿瘤患者,采用随机数...目的探讨叙事护理在肿瘤患者经外周静脉置入中心静脉导管(peripherally inserted central catheter,PICC)留置期间延续性护理中的应用效果。方法选取2023年12月—2024年5月在厦门大学附属第一医院行PICC维护的100例肿瘤患者,采用随机数字表法分为试验组和对照组各50例,试验组给予叙事护理模式进行延续护理,对照组给予常规延续护理,比较2组干预前后自我倡权、生活质量、并发症及依从性。结果干预后试验组自我倡权总分为(87.67±3.73)分,高于对照组的(71.90±7.15)分,差异有统计学意义(P<0.001)。干预后试验组总体健康状况评分为(77.55±8.87)分,高于对照组的(70.31±12.27)分,差异有统计学意义(P<0.05);试验组躯体功能、角色功能、情绪功能、社会功能评分均高于对照组,疲劳、恶心呕吐、食欲减退、腹泻评分均低于对照组,差异有统计学意义(P<0.05)。干预后试验组并发症发生率为10.2%,低于对照组的37.5%,差异有统计学意义(P<0.05)。干预后试验组导管维护缺失次数、缺失患者例数占比分别为1.9%、10.2%,低于对照组的8.0%、27.1%,差异有统计学意义(P<0.05)。结论叙事护理可提高肿瘤患者自我倡权水平,改善生活质量并提高患者导管维护依从性,降低并发症发生率。展开更多
目的:探究基于跨理论模型(trans-theoretical model,TTM)的延续护理干预在癌症经外周中心静脉置管(peripherally inserted central catheter,PICC)带管出院患者居家应用的必要性。方法:选取2022年6月—2023年6月在普洱市人民医院行PICC...目的:探究基于跨理论模型(trans-theoretical model,TTM)的延续护理干预在癌症经外周中心静脉置管(peripherally inserted central catheter,PICC)带管出院患者居家应用的必要性。方法:选取2022年6月—2023年6月在普洱市人民医院行PICC并带管出院的96例癌症患者,按随机数表法分为两组。对照组(n=48)给予常规延续护理,研究组(n=48)在此基础上接受基于TTM的延续护理。比较两组PICC相关并发症发生情况、自我管理能力、护理满意度及生活质量。结果:研究组PICC相关并发症总发生率为12.50%,比对照组的33.33%低,差异有统计学意义(P<0.05)。研究组自我管理能力各维度评分及总分均比对照组高,差异有统计学意义(P<0.05)。研究组护理总满意度为95.83%,比对照组的81.25%高,差异有统计学意义(P<0.05)。研究组生活质量各维度评分及总分均比对照组高,差异有统计学意义(P<0.05)。结论:基于TTM的延续护理干预在癌症PICC带管出院患者居家应用效果较好,可明显降低导管相关并发症发生率,提升患者自我管理能力及生活质量,提高满意度。展开更多
基金Sponsored by the National Natural Science Foundation of China(Grant No.51205095)Support Program for Key Youth(Grant No.1154G39)
文摘A large amount of cutting heat is produced during the heavy cutting process,and insert life is restricted by the effect of thermal load.The thermal load experiment of cemented carbide SCS,WF and YT15 is carried out,and the results show that the bending strength and fracture toughness of cemented carbide material decrease obviously under cyclic thermal load,while in the cooling process,the material mechanical property changes worse suddenly.The high-temperature mechanical property of SCS is the most stable,and that of YT15 is the worst.Further,a relation model among cutting temperature,cutting parameters and insert life is established.Finally,the measures to improve heavy cemented carbide inserts life are summarized from the aspects of cutting parameters selection,insert optimization design and TiCN,Al2O3,TiN complex insert coating.The research results are expected to provide support and reference for heavy cutting technology and insert technology.
文摘<span style="font-family:Verdana;">A metal matrix composite constitutes a continuous metallic matrix and a </span><span style="font-family:Verdana;">discontinuous phase known as reinforcement. The hybrid metal matrix composites</span><span style="font-family:Verdana;"> (Hmmcs) have been used to manufacture drive shafts, disc brake rotors, brake drums, connecting rods pistons, engine block cylinder liners for automotive and rail vehicle applications. The Hmmcs castings of diameter 120 mm and length 300 mm were prepared through sand mould technique following stir casting methodology. The cast components further subjected to evaluation of physical properties and machining tests using two grades of coated inserts and PCD inserts. The experiments were carried out following ISO 3685 standards. The coating thickness of the TiN coated and TiAlN coated inserts were measured using Kalo testing method</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">;</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> the results of the test show that the interface of the substrate and coating was free from the porosity, and the coating thickness of TiN coating was 4.84 microns and TiAlN coating was measured 4.6 microns. The results of the experiments show that performance of the PCD insert was better than coated inserts at 0.1 mm/rev feed</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">;</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> however at 0.2 mm/revolution feed PCD insert failed by micro chipping of cutting edge while machining Hmmcs. When TiAlN coated inserts were used to machine Hmmcs the coated inserts failed by gradual wear and BUE formation.
文摘The requirements of high quality machined surface as well as demand of enhanced contact time of cutting tools drive towards adopting multilayer coated carbide inserts. The industry requires higher productivity, hence higher machining parameters need to be used in order to meet the industry requirements. The alloy steel material used to fabricate machine parts consists of alloying elements like nickel, chromium and molybdenum difficult to machine, since the cutting tool fails by high tool wear, if we use uncoated carbide inserts to machine alloy steels. Hence in the present research work it is intended to use tungsten carbide inserts coated with different coatings for the experiments. The turning experiments were carried out using different grades of uncoated and coated carbide inserts of identical tool signature. The cutting speed selected for the experiments was 100 to 500 m/min in steps of 100 m/min, and the feed per revolution was 0.1 mm to 0.4 mm in step of 0.1 mm. The experimentation was carried out following ISO3685 standards. The results of the experiments revealed that the surface roughness measured was the least at cutting speed 500 m/min and feed per revolution of 0.1 mm, however the chip breaking found better when the feed used was greater than 0.2 mm/revolution.
文摘目的探讨叙事护理在肿瘤患者经外周静脉置入中心静脉导管(peripherally inserted central catheter,PICC)留置期间延续性护理中的应用效果。方法选取2023年12月—2024年5月在厦门大学附属第一医院行PICC维护的100例肿瘤患者,采用随机数字表法分为试验组和对照组各50例,试验组给予叙事护理模式进行延续护理,对照组给予常规延续护理,比较2组干预前后自我倡权、生活质量、并发症及依从性。结果干预后试验组自我倡权总分为(87.67±3.73)分,高于对照组的(71.90±7.15)分,差异有统计学意义(P<0.001)。干预后试验组总体健康状况评分为(77.55±8.87)分,高于对照组的(70.31±12.27)分,差异有统计学意义(P<0.05);试验组躯体功能、角色功能、情绪功能、社会功能评分均高于对照组,疲劳、恶心呕吐、食欲减退、腹泻评分均低于对照组,差异有统计学意义(P<0.05)。干预后试验组并发症发生率为10.2%,低于对照组的37.5%,差异有统计学意义(P<0.05)。干预后试验组导管维护缺失次数、缺失患者例数占比分别为1.9%、10.2%,低于对照组的8.0%、27.1%,差异有统计学意义(P<0.05)。结论叙事护理可提高肿瘤患者自我倡权水平,改善生活质量并提高患者导管维护依从性,降低并发症发生率。
文摘目的:探究基于跨理论模型(trans-theoretical model,TTM)的延续护理干预在癌症经外周中心静脉置管(peripherally inserted central catheter,PICC)带管出院患者居家应用的必要性。方法:选取2022年6月—2023年6月在普洱市人民医院行PICC并带管出院的96例癌症患者,按随机数表法分为两组。对照组(n=48)给予常规延续护理,研究组(n=48)在此基础上接受基于TTM的延续护理。比较两组PICC相关并发症发生情况、自我管理能力、护理满意度及生活质量。结果:研究组PICC相关并发症总发生率为12.50%,比对照组的33.33%低,差异有统计学意义(P<0.05)。研究组自我管理能力各维度评分及总分均比对照组高,差异有统计学意义(P<0.05)。研究组护理总满意度为95.83%,比对照组的81.25%高,差异有统计学意义(P<0.05)。研究组生活质量各维度评分及总分均比对照组高,差异有统计学意义(P<0.05)。结论:基于TTM的延续护理干预在癌症PICC带管出院患者居家应用效果较好,可明显降低导管相关并发症发生率,提升患者自我管理能力及生活质量,提高满意度。
