Cu/(SiC)p金屬基複合材料以同質與異質基材進行固態擴散接合之研究

Study on solid state of diffusion bonding for Cu/(SiC)p MMC using similar/dissimilar interlayer

范富翔(Hsiang-Fu Fan)

指導教授 ： 莊正利

中山醫學大學/健康管理學院/職業安全衛生學系碩士班/碩士(2014年)

https://doi.org/10.6834/CSMU.2014.00206

摘要

銅基碳化矽複合材料廣泛應用於汽車之煞車片或航太工業等，但銅基碳化矽複合材料之成品多為淨形(Net shape)或近淨形(Near-net-shape)尺寸之零件，使製造完成之成品不易加工或接合。為突破銅基碳化矽複合材料之應用上限制，銅基碳化矽複合材料之接合製程以熔融焊接為其主要方法，但熔融焊接過程中易伴隨輻射線、金屬燻煙、高溫且具有感電之潛在危害，容易導致作業人員產生白內障、肺部病變及感電致死等職業災害，且因金屬基複合材料之強化材與基材間比重不同，熔融焊接容易使焊件中強化材產生偏析、雜質混入，致使接合處出現氣泡與孔洞等缺陷，進而影響銅基碳化矽複合材料之接合品質，故需發展低危害與高性能之接合技術應用於銅基碳化矽複合材料。本實驗以固態擴散接合(diffusion bonding)原理及熱壓法(hot-pressing)取代傳統熔接之接合技術，在低於材料熔點之製程溫度下，接合銅基碳化矽複合材料，選用銅箔與鋁箔作為接合層材料，探討以不同接合層進行接合之品質及接合形態。製程參數選用之製程溫度為450℃- 600℃、碳化矽強化材含量為5 wt%-30 wt%、燒結之持溫時間為30 min-120 min。實驗結果顯示當持溫時間提升，可促進銅基材與銅接合層材料間原子交互擴散，有助於提升銅基碳化矽複合材料接合之相對密度及剪切強度；當碳化矽含量逐漸增加時，銅基複合材料接合之緻密度及剪切強度下降，因銅基複合材料之接合介面散佈強化材顆粒，阻礙基材與接合層材料之交互擴散進而形成脫層缺陷，此現象顯示高含量碳化矽之接合區未能形成有效接合，故其強化效果隨之下降；製程溫度增加時，可提升進銅基材與銅接合層材料間原子交互擴散，減少脫層缺陷，顯示提升製程溫度有助於改善接合試片之接合品質；比較不同接合層材料與直接接合時，以同質材料進行接合之接合強度最高，次等為直接接合，最弱之接合強度為異質材料之接合，因同質材料進行接合時，銅基材與銅接合層材料性質相同不易產生化學反應，且使用軟性金屬之接合層材料可提升接合介面之完整性，故可提升銅基複合材料之接合品質，直接接合銅基碳化矽複合材料時，因銅基碳化矽複合材料硬度較硬，未加入軟性之金屬接合層進行接合時，接合區域易造成不連續之接合，以異質材料接合時，因銅與鋁進行擴散反應，使接合區域形成脆性之介金屬化合物，且高含量之碳化矽阻礙銅基材與鋁接合層材料之交互擴散，因此未能形成有效接合，故碳化矽含量高之銅基碳化矽複合材料未能接合成功。

關鍵字

同質與異質接合層之接合 ； 銅基碳化矽複合材料 ； 熱壓法

並列摘要

The metal matrix composite (MMC) was widely used in automobile and aerospace. However it is difficult to machining and welding, the components was thus made to net shape or near-net-shape. To expand the application of MMC, the traditional fusion welding process was used to weld the components of MMC. However, it has several potential hazardous factors, high temperature, fume, toxic gases, and radiations. Those hazards will affect the labor’s health and safety. Furthermore, the density of reinforcement is lighter than that of metal matrix, thus a segregation defect would form when the traditional fusion welding process was applied to join the metal matrix composite. In this study, the solid state diffusion bonding process, hot pressing method was used to join Cu/(SiC)p metal matrix composite. To compare the different interlayers for bonding quality, aluminum foil and copper foil with a thickness 50 μm was selected as a bonding layer, and a direct bonding of Cu/(SiC)p MMC without using interlayer. The major bonding parameters of solid state diffusion bonding, bonding durations, bonding temperature, and fraction of reinforcement were investigated. The bonding strength of MMCs was evaluated using a shear test, the observation and compositions identified on the fracture surfaces were using optical microscopy (OM) and scanning electron microscope (SEM). The phase identified was using Electron Probe X-ray Microanalyzer (EPMA). Hardness measurements were conducted using a 100g load with a testing time of 15s. The experiment result showed that the Cu/(SiC)p MMCs bonded successfully using the hot pressing process. With increasing bonding temperature and bonding durations , the relative density increased and the shear strength increased. An elevated bonding temperature enhances the atomic interdiffusion between Cu/(SiC)p base metal and the Cu interlayer. However, at high fractional SiC of Cu/(SiC)p MMCs, its relative density and the shear strength were decreased because the SiC particles clusters at bonding interface to obstruct the atomic interdiffusion, and the delamination was formed at bonding interlayer. With increasing bonding durations, the atom has enough time to conduct atomic interdiffusion and to improve the bonded quality. A dissimilar interlayer to bond Cu/(SiC)p MMCs using the hot pressing process conducted, the crack was formed due to different of coefficient thermal expansion (CTE) between Cu/(SiC)p and Al interlayer. For Cu/(SiC)p MMCs bonded without interlayer, its bonding quality would be degreed when a high fractional SiC reinforcement in Cu/(SiC)p MMCs, because SiC particles at bonding interface would obstruct atomic interdiffusion from a good bonding strength. Therefore, a good bonding quality can be achieved for Cu/(SiC)p MMC bonding with the Cu interlayer.

並列關鍵字

Solid state diffusion bonding ； Similar/Dissimilar interlayer ； Cu/(SiC)p MMC

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