氧化锆对粉末冶金摩擦材料摩擦磨损性能的影响

利用MM-1000摩擦磨损试验机,比较分析了SiO2、Al2O3和ZrO2三种摩擦组元对材料摩擦磨损性能的不同作用,并系统研究了不同含量氧化锆及其粒度对粉末冶金摩擦材料摩擦磨损性能的影响.实验结果发现,在材料中添加适当含量和粒度的氧化锆可以使材料在高转速下具有良好的摩擦性能,且各种转速下都具有最小和稳定的磨损量.     

α-SiC的粒度对铜基摩擦材料摩擦磨损性能的影响

选取粒度为1μm和10μm的立方型6Hα-SiC陶瓷颗粒,制备含碳化硅陶瓷颗粒的铜基粉末冶金摩擦材料。通过扫描电镜(SEM)观察分析该材料的摩擦表面和亚表面的显微组织形貌,研究α-SiC粒度对铜基摩擦材料摩擦磨损性能的影响。结果表明:α-SiC陶瓷颗粒的加入可显著降低铜基摩擦材料的磨损,并能有效抑制材料缺陷源处微裂纹的萌生和扩展。SiC陶瓷颗粒的粒度对铜基摩擦材料机械混合层的形貌和抵抗摩擦过程中剪切变形的能力有显著影响,10μmα-SiC陶瓷颗粒能有效强化基体,显微硬度较不含α-SiC的材料提高1倍以上,表现出较优异的摩擦磨损性能,摩擦因数和摩擦因数稳定性最高,分别为0.31和0.58,磨损量最小。     

石墨粒度对Cu-Fe基摩擦材料性能的影响

研究了石墨粒度对Cu-Fe基摩擦材料性能的影响,发现随着石墨粒度的细化,材料的硬度升高,强度降低,材料及对偶的磨损增大,对材料的摩擦因数也有所影响。     

天然纤维增强聚合物基摩擦材料的研究

文章介绍了天然纤维主要是剑麻纤维与苎麻纤维的组成与性能,总结了剑麻纤维与苎麻纤维常用的物理和化学改性方法;简述了几种潜在能作为摩擦材料基体的热塑性树脂的性能,综述了天然纤维增强聚合物基复合材料以及天然纤维增强聚合物基摩擦材料的研究进展,最后得出由于天然纤维以及热塑性树脂的优异性能,天然纤维增强热塑性树脂摩擦材料的研究将会产生重大意义。     

CF/CVD/树脂炭复合材料的摩擦性能

采用针刺炭纤维整体毡作为骨架，经CVD致密，树脂浸渍固化增密及炭化，石墨化后制得C/C复合材料，研究了CVD炭和树脂炭含量对摩擦性能的影响。实验结果表明：CVD炭具有典型显微组织是材料具有良好摩擦性能的保证；C/C复合材料中加入适量的树脂炭不会影响材料的摩擦性能；摩擦系数大小不一定和摩损率成对应关系。     

偶联剂改性硅灰棉对树脂基摩擦材料摩擦学性能的影响

硅灰棉是树脂基摩擦材料常用的主要组分之一,分别采用硅烷偶联剂CX-602与KH-550,以及钛酸酯偶联剂TCA-201与TCA-311w对硅灰棉进行表面改性,以期改善材料的摩擦磨损性能。利用D-MS150定速实验机和ZYMM-1000缩比台架试验机(1:6)对摩擦材料试样进行摩擦磨损性能测试,研究偶联剂改性硅灰棉对树脂基摩擦材料结构与摩擦学性能的影响。结果表明,用KH-550表面改性硅灰棉制备的树脂基摩擦材料的摩擦磨损性能最佳,高温摩擦因数比未改性的试样提高22%,并且摩擦因数的稳定性最好,热衰退率最低(14%),摩擦试验后的质量损失和厚度损失都最小,分别为1.38 g和1.04 mm。     

钢纤维与硅氧铝陶瓷纤维对树脂基摩擦材料性能的影响

钢纤维和陶瓷纤维由于各自的特性在摩擦材料行业中成为非常重要的非石棉纤维.采用粉末冶金法制备纤维增强树脂基摩擦材料,对比研究以钢纤维和硅氧铝陶瓷纤维作为增强材料对树脂基摩擦材料摩擦和磨损性能的影响.结果表明,硅氧铝陶瓷纤维和钢纤维对材料摩擦因数和磨损率的影响均较复杂;钢纤维的添加量(质量百分数)为20%-25%、硅氧铝陶...     

石墨对铜基粉末冶金闸片材料性能的影响

采用粒度>550μm的天然鳞片石墨和人造石墨配合制备了铜基粉末冶金高速列车制动闸片材料,系统研究了鳞片石墨粒度对材料力学性能、摩擦磨损性能和摩擦膜形成的影响。结果表明:采用粒度>550μm的天然鳞片石墨作润滑组元,所制备摩擦材料的抗压强度显著高于采用小粒度石墨所制材料,达到145.30MPa;随鳞片石墨粒度的增大,材料的摩擦系数降低,磨损率降低幅度可达50%以上,摩擦表面趋于形成完整的摩擦膜;采用鳞片石墨和人造石墨配合使用,能够显著提高材料强度。     

一种新型陶瓷基汽车刹车片摩擦磨损性能的研究

利用无机纤维和有机纤维(无金属纤维)混杂增强,采用无机粘结剂(无树脂或少量树脂)和有机或无机材料作为摩擦性能调节剂,通过特定工艺制备新型陶瓷基汽车刹车片。研究了这种新材料的物理、力学性能和摩擦磨损性能,并与树脂基摩擦材料进行了性能对比。研究结果表明:新型陶瓷基摩擦材料密度适中(约2.0 g.cm-3),在相同条件下新型陶瓷基刹车片的磨损率远远低于树脂基刹车片,且其摩擦系数稳定性、抗热衰退性能及制动舒适性均明显高于树脂基摩擦材料。     

SiC粒度对铁基粉末冶金摩擦材料性能的影响

本文采用冷压、加压烧结的方法制备了含Si C颗粒的铁基粉末冶金摩擦材料。研究了不同粒度规格(485μm~、250~830μm、180~380μm、150~180μm、75~150μm、~120μm)的Si C对某铁基粉末冶金摩擦材料密度、硬度、摩擦磨损性能等的影响。结果表明:Si C粒度的变化对铁基粉末冶金摩擦材料压坯密度、烧结后硬度及结合性影响较小;随着Si C粒径的减小,铁基粉末冶金摩擦材料的硬度、最大摩擦系数、最小摩擦系数和平均摩擦系数均逐渐减小,磨损量逐渐增大,力矩曲线波动逐渐变大;Si C粒度在180~830μm(-20+80目)时,铁基粉末冶金摩擦材料表现出较优异的摩擦磨损性能。     

China's Major Non-ferrous Metals Imports & Exports

正~~     

Zinc Production by Province in 2014

正~~     

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.