生物医用Ti6Al4V合金粉末注射成形工艺研究

钛及钛合金具有高比强度、低弹性模量、优良的耐蚀性和绝佳的生物相容性,但较差的加工性能大大限制了其应用范围。钛及钛合金金属粉末注射成形工艺克服了机加工、模压等传统加工工艺的缺点,结合传统粉末冶金和注塑成型的优势,实现了结构复杂的钛及钛合金产品低成本、大批量近净成形,提高了材料利用率。本文利用水溶性黏结剂和粉末粒度为16 μm和22 μm的商用球形Ti6Al4V合金粉制备了注射料和相应的试样,通过实验确定了气氛热脱黏结合真空烧结的最佳工艺,基于该工艺制备得到了两种注射料的烧结试样。结果表明:粉末粒度为16 μm注射料烧结件杂质含量未能满足外科植入用金属注射成形Ti6Al4V组件标准;粉末粒度为22 μm注射料烧结件物理化学性能如下,极限拉伸强度880 MPa,屈服强度830 MPa,延伸率13.2%,相对密度96.8%,氧质量分数为0.195%,氮质量分数为0.020%,碳质量分数为0.022%,该试样整体性能满足外科植入用金属注射成形Ti6Al4V组件标准。     

生物医用纯钛的粉末注射成形研究

钛和钛合金由于具有诸如高比强度、低弹性模量、优异的耐腐蚀性以及生物相容性等一系列优良的综合性能,成为目前最有前景的生物医用材料,但是其较差的机加工性能限制了钛材料的应用,尤其是在形状复杂零件中的应用。金属粉末注射成形(MIM)可以实现复杂形状产品的近终成形,这种成形工艺能够大大扩展钛及钛合金的应用范围。利用水溶性注射料进行了力学性能测试试样的制备,通过优化工艺参数,最终获得了相对密度为95.7%的纯钛烧结件,其他主要理化性能如下:氧质量分数0.196%,氮质量分数0.007%,屈服强度403.12 MPa,极限抗拉强度491.33 MPa,伸长率21.4%,除相对密度外其他性能均满足ASTM F2989-13二级纯钛标准。     

生物医用纯钛的粉末微注射成形工艺研究

钛材料作为目前生物医用性能最好的材料,具有一系列的优良性能,如高比强度、低弹性模量、优良的耐磨耐蚀性和优异的生物相容性。金属粉末微注射成形(Micro MIM)技术作为一种新兴的微加工技术,为钛材料在生物医用微型植入物领域的应用提供了一种低成本、大批量、近净成形途径。利用微注射成形技术制备了纯钛微型试样,并对试样进行了脱粘和烧结。通过调整脱粘和烧结工艺参数,制得整体性能如下的试样:氧质量分数0.240%,氮质量分数0.028%,屈服强度450 MPa,极限抗拉强度565 MPa,伸长率18.0%,相对密度97.3%。试样的整体性能满足ASTM F2989-13外科植入用金属微注射成形纯钛构件要求。     

钴对凝胶注模成形医用植入钛合金材料的影响

本文采用凝胶注模成形工艺,用钴包覆钛粉制备多孔钛合金植入材料。研究了钴对成形工艺中浆料的粘度、孔隙率以及烧结体的抗压强度的影响,预混液中有机单体的浓度、单体(AM)/交联剂(MBAM)的比例对坯体的强度的影响。通过改变烧结温度和固相含量,可以实现多孔钛钴合金的孔隙率和抗压强度分别在29%~58%、68~378 MPa范围内调节,采用含钴8%的钴包覆钛粉以33%的固相含量制备坯体,在1 130℃保温2 h制备的多孔钛合金材料,孔隙率为45.6%、抗压强度为227 MPa、抗弯强度为213 MPa、弹性模量为15.8 GPa,力学性能与自然骨接近,适宜做自然骨替代材料。     

钛及钛合金金属粉末注射成形技术的研究进展

钛及钛合金兼具低比重、高比强度、优异的生物相容性和良好的耐腐蚀性,在航空航天、生物医疗、化工、汽车等领域有极大的应用潜力。钛及钛合金金属粉末注射成形技术(metal injection molding,MIM)能够实现中小型复杂形状钛产品的大批量、低成本制备,对于推动钛及钛合金产品的生产及应用具有重要意义。本文介绍了金属粉末注射成形钛及钛合金的特点及优势,从粉末原料、黏结剂体系、粉末注射成形、脱黏和烧结等方面综述了钛及钛合金金属粉末注射成形技术的研究进展,并针对目前存在的主要问题,分析了金属粉末注射成形钛及钛合金的研究方向及发展前景。     

粉末注射成形钛合金粘结剂体系的研究进展

钛及钛合金具有低比重、高比强度、优异的生物相容性以及良好的耐腐蚀性等特点,在航空航天、生物医疗、化工、船舶、汽车等领域极具应用潜力。钛合金粉末注射成形技术（powder injection molding,PIM）提高了材料的利用率,实现了中小型复杂形状钛产品的大批量、低成本制备,显著地推动了钛及钛合金产品的生产及应用。目前关于粉末注射成形钛合金粘结剂体系的相关文献报道十分有限,新型粉末注射成形钛合金粘结剂体系的开发处于停滞不前的状态。本文分析总结了不同粉末注射成形钛合金粘结剂体系的研究现状,并针对目前存在的问题提出改进措施。     

医用多孔钛植入材料凝胶注模成形工艺研究

采用凝胶注模成形工艺制备了大尺寸、复杂形状医用多孔钛植入材料,其孔隙度为46.5%、开孔隙度为40.7%,抗压强度为158.6MPa、杨氏模量为8.5GPa,与自然骨基本匹配,适合作为人造骨替代材料.研究了预混液中有机单体的浓度、单体(AM)/交联剂(MBAM)比例以及固相含量对钛粉浆料表观黏度以及坯体强度的影响,并得到了最佳工艺参数;讨论了不同烧结工艺时烧结体的孔隙度以及力学性能的变化,发现在1373K保温1.5h是凝胶注模成形多孔钛植入材料较为合适的烧结工艺参数.     

注射成形纯钛脱粘和烧结工艺研究

粉末注射成形是制造复杂形状钛及钛合金零件的合适工艺。本文利用氢化脱氢（HDH）钛粉制备注射成形纯钛材料，研究了溶剂脱粘、热脱粘和真空烧结工艺对粘结剂脱除率、烧结显微组织和力学性能的影响。结果表明：溶剂脱粘的适宜温度为50～60℃，4h后可以脱除97％以上的可溶性粘结剂；在随后的真空热脱粘过程中，在200-450℃高温阶段降低升温速率、延长保温时间，有利于脱除剩余聚合物粘结剂；真空烧结温度为1250℃时，烧结致密度可高达98％，但表层易形成硬质TiC相和微量TiO2相；在该温度下烧结1．5h，制品抗拉强度和伸长率分别提高到349MPa和6．4％，继续延长烧结时间会导致拉伸性能下降。     

粗粉末金属注射成形烧结件的性能

对平均粒度分别为65.71μm, 26.69μm和19.25μm的3种较粗(相对于一般注射成形用细粉而言)水雾化316L不锈钢粉末进行了注射成形, 讨论了粉末粒度对金属注射成形烧结件性能, 如烧结密度、孔隙形貌、金相组织和力学性能的影响。结果表明, 只要工艺控制得当, 三种粗粉末都能用于金属注射成形, 且可得到比细粉更小和更稳定的烧结收缩率, 较高的密度, 较好的拉伸强度、屈服强度、硬度等力学性能。其中平均粒径为19.25μm粉末的烧结样品的力学性能为: 抗拉强度506 MPa、屈服强度193 MPa、延伸率54%、硬度HRB61, 达到并超过了美国MPIF关于316L不锈钢细粉末注射成形烧结件的性能标准值。     

基于氢化脱氢钛粉制备低成本高性能钛合金

粉末冶金是短流程制备低成本、高性能钛及钛合金的有效方法之一。采用氢化脱氢(HDH)制粉—冷等静压成形—真空烧结致密化的技术路线制备了间隙原子含量低(O 0. 16%、N 0. 05%、H 0. 015%,质量分数)、具有均匀细小近等轴α组织且室温拉伸性能(R_m为840～950 MPa、R_(P0. 2)为770～900 MPa、A为12%～16%)良好的Ti-6Al-4V合金烧结坯,证明了HDH工艺制备低间隙原子含量钛粉的可行性,而间隙原子含量的增加主要源于粉末及压坯的操作、转移和储存过程。由于粉末冶金钛合金具有细晶和近净成形的特点,无需开坯锻造,并且近净成形的烧结坯能够提高材料利用率,减少后续热加工变形量及加工道次。因此,以粉末钛合金烧结坯替代锻坯进行后续的塑性加工能够大幅度降低钛合金构件及型材的成本。     

China's Major Non-ferrous Metals Imports & Exports

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Zinc Production by Province in 2014

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80% of Chinese Firms Purchasing Overseas Mines Ended up in the Red

<正>Minmetals Resources acquired the world’s largest copper mine under construction for USD5.85 billion.One after another,listed companies Jien Nickle,China Molybdenum and Chihong Zinc and Germanium raised money to get involved in overseas mining projects…SOEs and private enterprises are engaged in a frenzy of overseas mine purchasing.A reporter with Economic     

Copper Processing Profit Dropped Sharply,Copper Consumption Will Face Impact in the Second Half of the Year

正Judging from China’s copper consumption field,the biggest consumption unit is electric power,which accounts for 47%of total consumption;it is followed by light industry sector,including household electrical appliance,machinery,durable goods and hardware etc,which accounts for 22%of total consumption;followed by transportation field,     

Central Geological Prospecting Fund Newly Added 16.47 Million Tonnes of Bauxite in 2013

正In 2013,the Central Geological Prospecting Fund(CGPF)Project newly discovered 15 ore fields,including 3 large above ore fields,and 5medium sized ore fields.The reporter learned from the recently published"Annual Report of Central Geological Prospecting Fund Project(2013)"that,from 2006 to 2013 the CGPF     

Manufacturers of Copper Tube for Central Air Conditioner Use Face Mounting Pressure in the Final Quarter of the Year

正This year,the investment growth rate of real estate industry continued to slow down,sold area of commercial housing also dropped significantly,which brought huge pressure to the domestic air conditioning manufactures.In the first half of the year,by relying on high growth in national financial expenditure,along with investment in public infrastructure     

Xinjiang Ranks No.1 in Production of Primary Aluminum in China

正Kang Yi,Honorary Chairman of China Nonferrous Metals Industry Association,said recently at the Forum on Development of the Non-ferrous Metals Industry in Central and Western China held in Zhengzhou that,as more and more electrolytic aluminum factories in Xinjiang came into operation,the electrolytic aluminum output of Xinjiang had reached2,275,000 tons in the first 7 months this year,     

Shenhuo Coal Industry and Electricity Power Completed800,000 t/a Aluminum Project in Xinjiang

正"Xinjiang project has been completed according to schedule,but total completion and total start of production are two different concepts,after completion it still needs a gradual process of reaching production target."On the morning of November 3,Shenhuo Coal Industry and Electricity Power told investors the above statement on the investor interaction platform.     

Guangdong Metal Transaction Center has Become the Second Largest Precious Metal Transaction Platform Nationwide

正The reporter learned from Guangdong Province Precious Metal Transaction Center that in 2013the Center maintained healthy development momentum,and had become the second largest precious metal transaction platform in China in terms of market size;currently Guangdong is quickening steps of financial innovation for the Center,aiming to build a transaction center with international core competitiveness.     

Seven Rare Earth Projects Involving Close to 3 Billion Yuan Investment Landed In the HighTech Zone

正On May 22,Baotou Rare Earth Industry Cooperation Consultation MeetingProject Agreement-signing Ceremony was held in Ningbo,nearly 40 enterprises from Ningbo,Guangdong,Hunan,and Shanxi participated in project consultation.After multi-lateral communication,agreements were signed for a total of 7 rare earth projects successfully.