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Preliminary Study on Some Properties of Co-Cr Dental Alloy Formed by Selective Laser Melting Technique 被引量:5
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作者 张飚 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2012年第4期665-668,共4页
The surface condition, some properties and ion releasing behavior of cobalt-chromium (Co-Cr) dental alloy formed by selective laser melting (SLM) technique were investigated. Before porcelain fused firing, the sur... The surface condition, some properties and ion releasing behavior of cobalt-chromium (Co-Cr) dental alloy formed by selective laser melting (SLM) technique were investigated. Before porcelain fused firing, the surface condition of the Co-Cr alloy was observed using a scanning electron microscope (SEM), and then the density and hardness were examined. After porcelain fused firing, the interface of porcelain and alloy was observed, and then the metal-ion release of the samples was tested. SLM technique provides Co-Cr alloy higher hardness than casting method. After degassing-oxidation procedure and porcelain fused firing, the interface of the alloy and porcelain showed excellent combination. Co ion was more than Cr ion released from SLM Co-Cr alloy, the amounts of Co and Cr ions were safe according to ISO security criterion. Considering the properties before and after porcelain fused sintering process, SLM technique is suitable for dental Co-Cr alloy restoration. 展开更多
关键词 SLM DENTAL co-cr alloy
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Metal-ceramic Bond Mechanism of the Co-Cr Alloy Denture with Original Rough Surface Produced by Selective Laser Melting 被引量:7
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作者 ZHANG Sheng LI Yong +3 位作者 HAO Liang XU Tian WEI Qingsong SHI Yusheng 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2014年第1期69-78,共10页
The porcelain fracture caused by low metal-ceramic bond strength is a critical issue in porcelain fused to metal(PFM) restorations. Surface roughening methods, such as sand blasting, acid etching and alkaline degrea... The porcelain fracture caused by low metal-ceramic bond strength is a critical issue in porcelain fused to metal(PFM) restorations. Surface roughening methods, such as sand blasting, acid etching and alkaline degreasing for the metal matrix are used to increase bond strength. However, the metal matrix of PFM processed by selective laser melting(SLM) has natural rough surface. To explore the effect of the original roughness on metal-ceramic bond strength, two groups of specimen are fabricated by SLM. One group of specimen surface is polished smooth while another group remains the original rough surface. The dental porcelain is fused to the specimens' surfaces according to the ISO 9693:1999 standard. To gain the bond strength, a three-point bending test is carried out and X ray energy spectrum analysis(EDS), scanning electron microscope(SEM) are used to show fracture mode. The results show that the mean bond strength is 116.5 16 MPa of the group with rough surface(Ra= 17.2), and the fracture mode is cohesive. However, when the surface is smooth (Ra =3.8), the mean bond strength is 74.5 MPa _+ 5 MPa and the fracture mode is mixed. The original surface with prominent structures formed by the partly melted powder particles, not only increases surface roughness but also significantly improves the bond strength by forming strong mechanical lock effect. Statistical analysis (Student's t-test) demonstrates a significant difference (p〈0.05) of the mean value of bond strength between the two groups. The experiments indicate the natural rough surface can enhance the metal-ceramic bond strength to over four times the minimum value (25 MPa) of the ISO 9693:1999 standard. It is found that the natural rough surface of SLM-made PFM can eliminate the porcelain collapse defect produced by traditional casting method in PFM restorations. 展开更多
关键词 selective laser melting(SLM) co-cr alloy metal-ceramic bond strength
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The Effect of Argon Inert Gas on the Laser Welding Quality of Co-Cr and Ni-Cr Base Metal Alloys
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作者 Sklavou Efthymia Poulis Nikolas Prombonas Anthony 《Journal of Biomedical Science and Engineering》 2021年第12期442-451,共10页
The purpose of this research was to study the effect of Argon inert gas on the laser welding quality of Co-Cr and Ni-Cr base metal alloys, which are widely used as Fixed Prosthodontics alloys in Dental Laboratories. A... The purpose of this research was to study the effect of Argon inert gas on the laser welding quality of Co-Cr and Ni-Cr base metal alloys, which are widely used as Fixed Prosthodontics alloys in Dental Laboratories. A total of 36 specimens were manufactured (18 of Ni-Cr alloy and 18 of Co-Cr alloy). The specimens were then divided into 3 subgroups (6 specimens each): control;argon-welded;and non-Argon welded. The specimens were cut, laser welded, radiographed and finally tested under tensile strength testing, followed by examination using Scanning Electron Microscopy. The tensile strength of welded specimens was lower than the strength of non-welded specimens, however this difference was not found to be statistically significant. The material factor (Co-Cr alloy or Ni-Cr alloy) has a statistically significant effect on the tensile strength, while the presence or not of the inert gas, as well as the combination of the two factors do not have a statistically significant effect. The laser welding process applied in daily practice (separation of specimen, formation of two cones in contact, aggregation of two cones, filling of the remaining gap by welding) is considered satisfactory in terms of weld strength. The factor of the material, as an independent factor, affects the tensile strength to a statistically significant degree, in contrast to the factor of the presence of inert gas which does not affect to a statistically significant degree. 展开更多
关键词 Laser Welding co-cr alloys Ni-Cr alloys Mechanical Properties ARGON No Argon Environment
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SG砂轮磨削钛合金烧伤机理 被引量:14
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作者 张红霞 陈五一 陈志同 《北京航空航天大学学报》 EI CAS CSCD 北大核心 2008年第1期22-26,共5页
钛合金以其良好的耐热耐腐蚀性和特别高的比强度在国内外航空航天工业上得到了广泛的应用.针对钛合金在磨削加工过程中极易发生的磨削烧伤问题,采用先进的测试方法,对磨削过程中磨削力、磨削温度、工件表面粗糙度及表面形貌、表面层金... 钛合金以其良好的耐热耐腐蚀性和特别高的比强度在国内外航空航天工业上得到了广泛的应用.针对钛合金在磨削加工过程中极易发生的磨削烧伤问题,采用先进的测试方法,对磨削过程中磨削力、磨削温度、工件表面粗糙度及表面形貌、表面层金相组织及显微硬度等变化规律进行了分析研究.研究结果表明,TC6钛合金在磨削温度超过600℃时即发生烧伤.表面形貌随磨削温度的升高而逐渐恶化.当发生严重烧伤时,工件表面有裂纹产生,其方向大致与磨削方向垂直.工件烧伤时材料表层的金相组织发生变化,α相颗粒明显粗大,使得钛合金的物理机械性能下降.研究结果为寻求优化的高效、高精度钛合金磨削加工工艺提供理论及实验依据. 展开更多
关键词 sg砂轮 钛合金 磨削烧伤机理
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SG砂轮磨削航空合金温度研究 被引量:2
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作者 张红霞 陈五一 马建峰 《工具技术》 北大核心 2008年第2期7-11,共5页
钛合金和高温合金的导热性差,磨削过程中产生的高温不仅加速砂轮的磨损,而且降低工件表面质量,磨削温度是影响磨削过程的重要参数。本文重点阐述了夹丝半人工热电偶法测温原理及标定方法,并对不同磨削条件下磨削航空合金的温度进行了实... 钛合金和高温合金的导热性差,磨削过程中产生的高温不仅加速砂轮的磨损,而且降低工件表面质量,磨削温度是影响磨削过程的重要参数。本文重点阐述了夹丝半人工热电偶法测温原理及标定方法,并对不同磨削条件下磨削航空合金的温度进行了实验研究。实验选用新型陶瓷氧化铝SG砂轮和普通GC砂轮,分析磨削温度信号的物理意义,系统地研究了磨削用量、磨削方式、砂轮类型以及工件材料对航空合金磨削时温度的影响,为航空合金的高效高精度磨削加工工艺优化提供实验依据。 展开更多
关键词 sg砂轮 航空合金 磨削温度
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SG砂轮磨削镍基合金GH4169砂轮磨损机理与磨削性能的实验评价 被引量:17
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作者 黄保腾 张彦彬 +5 位作者 王晓铭 陈云 曹华军 刘波 聂晓霖 李长河 《表面技术》 EI CAS CSCD 北大核心 2021年第12期62-70,共9页
目的减少磨削镍基合金GH4169过程中砂轮磨损和堵塞现象,提高工件表面质量。方法采用WA和SG砂轮磨削镍基合金GH4169,通过观察磨削前后砂轮表面微观形貌,研究两种砂轮表面材料粘附、堵塞以及磨粒破碎等主要磨损机制。从磨削力、工件表面... 目的减少磨削镍基合金GH4169过程中砂轮磨损和堵塞现象,提高工件表面质量。方法采用WA和SG砂轮磨削镍基合金GH4169,通过观察磨削前后砂轮表面微观形貌,研究两种砂轮表面材料粘附、堵塞以及磨粒破碎等主要磨损机制。从磨削力、工件表面形貌、磨削比能3个方面评价两种砂轮的磨削性能,并探究磨削参数对砂轮磨削力、工件表面形貌、磨削比能的影响规律。结果在去除相同体积材料时,SG砂轮的磨削力较小,所消耗的能量较WA砂轮低21.5%,SG砂轮所加工工件表面的粗糙度明显低于WA砂轮所加工工件表面的粗糙度,两者表面粗糙度差值均在1μm以上。SG砂轮表面材料粘附现象较轻,WA砂轮表面出现了大面积的材料粘附,造成了砂轮堵塞。结论 SG磨粒因内部致密的微小晶粒所决定的微破碎机制,使SG砂轮在磨削镍基合金GH4169过程中保持了锋利的磨削刃,减少了砂轮表面的材料粘附,同时也获得了良好的工件表面质量。另外,SG磨粒较WA磨粒具有更佳的力学性能,使其在去除相同体积材料时所消耗的能量更少。 展开更多
关键词 sg砂轮 镍基合金GH4169 磨削 砂轮磨损 微观形貌
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压水堆核电站蒸汽发生器用600合金管在含铅高温碱溶液中的应力腐蚀行为研究 被引量:4
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作者 但体纯 王俭秋 +1 位作者 韩恩厚 柯伟 《腐蚀科学与防护技术》 CAS CSCD 北大核心 2008年第5期313-316,共4页
采用U型弯曲试样研究了高、低温工厂退火状态的压水堆蒸汽发生器(SG)商用化600合金管在330℃、含10g/L PbO的10%NaOH高温水溶液中的应力腐蚀开裂(SCC)行为.结果表明,在氢浓度很高时,600合金表现为较严重的晶间腐蚀(IGA),最大侵蚀深度约... 采用U型弯曲试样研究了高、低温工厂退火状态的压水堆蒸汽发生器(SG)商用化600合金管在330℃、含10g/L PbO的10%NaOH高温水溶液中的应力腐蚀开裂(SCC)行为.结果表明,在氢浓度很高时,600合金表现为较严重的晶间腐蚀(IGA),最大侵蚀深度约270μm;没有观察到明显的应力腐蚀开裂,腐蚀晶界中有铅的沉积;冷拉预变形、退火温度对材料的腐蚀和应力腐蚀行为的影响不明显. 展开更多
关键词 600合金 应力腐蚀 晶间腐蚀 蒸汽发生器
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牙龈卟啉单胞菌和变形链球在不同方法制作的钴铬合金表面粘附能力的研究 被引量:1
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作者 陈敏 孙莹莹 黄玮 《全科口腔医学电子杂志》 2019年第17期15-16,19,共3页
本文对比评价了牙龈卟啉单胞菌和变形链球菌在激光烧结与铸造两种制作工艺下的钴铬合金表面粘附能力。两种制造方式制作AB两组钴铬合金试件,经打磨后在相同的粗糙度范围内,不同试件表面两种细菌的粘附量无统计学意义。结果表明激光烧结... 本文对比评价了牙龈卟啉单胞菌和变形链球菌在激光烧结与铸造两种制作工艺下的钴铬合金表面粘附能力。两种制造方式制作AB两组钴铬合金试件,经打磨后在相同的粗糙度范围内,不同试件表面两种细菌的粘附量无统计学意义。结果表明激光烧结钴铬合金(SLM)与传统铸造钴铬合金试件表面同一种细菌的粘附能力无明显差异。 展开更多
关键词 变形链球菌 牙龈卟啉单胞菌 激光烧结钴铬合金 sg钴铬合金
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Grain boundary character and stress corrosion cracking behavior of Co-Cr alloy fabricated by selective laser melting 被引量:2
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作者 Xin Dong Ning Li +7 位作者 Yanan Zhou Huabei Peng Yuntao Qu Qi Sun Haojiang Shi Rui Li Sheng Xu Jiazhen Yan 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2021年第34期244-253,共10页
In this work,we used the selective laser melting(SLM)fabricated Co-Cr alloy with prominent residual strain,extremely non-equilibrium microstructures,and low stacking fault energy as a precursor to fabricate materials ... In this work,we used the selective laser melting(SLM)fabricated Co-Cr alloy with prominent residual strain,extremely non-equilibrium microstructures,and low stacking fault energy as a precursor to fabricate materials with the optimal grain boundary character distribution.The grain boundary engineering(GBE)of the Co-Cr alloy was achieved by a simple heat treatment of the SLM-fabricated Co-Cr alloy.The obtained GBE Co-Cr alloy exhibited 81.47%of special grain boundaries(∑3^(n)n=1,2,3),while it substantially disrupted the connectivity of the random high-angle boundaries,successfully reducing the propensity of intergranular degradation.Slow strain rate tests(SSRTs)showed that the GBE Co-Cr alloy possessed lower stress corrosion cracking(SCC)susceptibility and higher ductility in the corrosive environment(0.9%Na Cl solution)than in the air.The high fraction of special boundaries,coupled with the stress-induced martensitic transformation(SIMT)in the GBE Co-Cr alloy yielded these results,which unique and rarely simultaneously satisfied for common structural materials.The current"SLM induced GBE strategy"offers a novel approach towards customized GBE materials with high SCC resistance and ductility in the corrosive environment,shedding new light on developing high-performance structural materials. 展开更多
关键词 Grain boundary engineering Selective laser melting co-cr alloy Stress corrosion cracking DUCTILITY
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