SiCp/Cu复合材料热膨胀性能研究

以电子封装基片为应用背景,采用挤压铸造方法制备了体积分数为55％,不同颗粒粒径增强的SiCp／Cu复合材料,并分析测试了颗粒粒径和热处理状态对材料热膨胀性能的影响规律．显微组织观察表明,复合材料颗粒分布均匀,材料组织致密;热膨胀性能测试表明,随着温度升高,复合材料的热膨胀系数呈非线性增加;SiC体积分数相同时,减小SiC颗粒尺寸有利于降低复合材料的热膨胀系数;退火处理可以减小基体中的热残余应力,有助于降低复合材料的热膨胀系数．     

SiCp/Cu复合材料高温抗氧化性能研究

采用粉末冶金方法制备了SiCp/Cu复合材料,研究了复合材料在恒温氧化和循环氧化条件下的抗氧化性能。结果表明：在400—700℃时,SiCp/Cu复合材料具有比纯铜优良的抗氧化性能;在温度一定的条件下,SiC体积分数为20%时,复合材料的抗氧化性能最好;在循环氧化条件下,随着氧化时间延长,复合材料氧化增重率逐渐增大,而且呈现近抛物线变化规律;对相同SiC颗粒含量的SiCp/Cu复合材料,SiC颗粒越细,试样的抗氧化性能越好。     

SiO2p／Ni和SiCp／Ni复合材料抗氧化性能研究

采用粉末冶金方法制备了SiO2p／Ni和SiCp／Ni复合材料，研究了两种复合材料在恒温氧化和循环氧化条件下的抗氧化性能。结果表明：两种复合材料比基体Ni有更好的抗氧化性能；复合材料SiO2p／Ni的抗氧化性能优于SiCp／Ni复合材料；复合材料的循环氧化速率高于恒温氧化速率。     

SiCp增强Al基复合材料浸润性的研究

利用半固态熔铸法制备ＳｉＣｐ／Ａｌ复合材料,探讨了在空气中将ＳｉＣｐ加入（纯Ａｌ＋添加剂）合金中时,ＳｉＣｐ的加入量、搅拌温度、浇注温度等因素对复合制备工艺的影响。结果表明,叶片在三层以上的搅拌器,以适当速度搅拌熔体时,可增加ＳｉＣｐ在体中的熔入量,且浸润性较好,分布均匀。     

SiC粒径对PTFE/SiCp复合材料耐磨性能的影响

利用机械混合法制备了不同粒径SiCp填充聚四氟乙烯（PTFE）复合材料PTFE／SiCp，并采用M－200型环－块材料磨损试验机在干摩擦条件下对其磨损特性进行了研究，并利用扫描电子显微镜（SEM）及能谱仪对复合材料的磨损表面和摩擦环表面进行了形貌观察及检测。结果表明：SiCp的加入大大提高了PTFE的耐磨性能，SiCp粒径的大小是影响复合材料耐磨性能及磨损机理的重要因素之一。     

SiCp／A356铝合金复合材料触变挤压研究

采用有限元软件DEFORM-3D^TM模拟SiCp／A356铝合金复合材料电子封装壳体的成形过程,应用等温压缩实验数据分析材料模型触变成形过程中金属流动速度场和温度场分布,并对可能产生的成形缺陷进行预测。研究发现,一模四件的模型更适合半固态触变成形,缺陷可能出现在最后成形的成形件侧棱两角。     

热处理对6061Al／SiCp复合材料阻尼性能的影响

采用喷射共沉积方法制备了6061Al/SiCp金属基复合材料（MMC）,研究了5种热处理制度对其组织和阻尼性能的影响。结果表明：不同热处理状态的材料,在常温下内耗值基本相同,而在高温下则存在显著差别。在100℃-270℃温度范围内,阻尼能力的大小顺序为：炉冷＞空冷＞－70℃淬火＞原料＞－195℃淬火＞水淬;在试验温度范围内（30℃-400℃）,模量随温度的升高表现为单调下降,随应变振幅的增加而增加;同一频率下,内耗值不随应变振幅发生变化。     

SiCp／Al复合材料技术研究开发和应用

本项目是西安工业大学利用液态搅拌法专利小批量制备SiCp／Al复合材料,并对其显微组织、界面结构、凝固行为,重熔铸造性能和机械加工工艺性等进行系统深入的研究．解决了液态搅拌法批量制备SIC颗粒与液态Al合金润湿困难、     

SiCp／Al复合材料技术研究开发和应用

本项目是西安工业大学利用液态搅拌法专利小批量制备SiCp／Al复合材料,并对其显微组织、界面结构、凝固行为,重熔铸造性能和机械加工工艺性等进行系统深入的研究．解决了液态搅拌法批量制备SIC颗粒与液态Al合金润湿困难、不易分散均匀、难以重熔精炼等技术难点,为该材料的工业化生产及应用奠定了基础．已具备制备大批量SiCp／Al复合材料的能力,现已制备的产品有大马力柴油机活塞、缸体水套等．     

SiCp／Al复合材料技术研究开发和应用

本项目是西安工业大学利用液态搅拌法专利小批量制备SiCp／Al复合材料,并对其显微组织、界面结构、凝固行为,重熔铸造性能和机械加工工艺性等进行系统深入的研究．解决了液态搅拌法批量制备SIC颗粒与液态Al合金润湿困难、不易分散均匀、难以重熔精炼等技术难点,为该材料的工业化生产及应用奠定了基础．     

Spark Effect on the Densification of SiCp/Al Composites by SPS

1 IntroductionSiCp/Al composites have aroused considerable inter-ests in manyfields of industry due to their tailorable me-chanical and thermophysical properties .SiCp/Al compos-ites have been developed mainly as structural materials inapplicationfor automobile industries and aerospace indus-tries . However ,thermal management applicationsin elec-tronic packaging,such as substrates ,heat slugs and heatspreads have been focused on. Electronic componentsused in thermal management applications …     

电子封装用高导热金刚石/铜复合材料的研究进展

金刚石/铜复合材料由于具有热导率高、热膨胀系数低等优异的特性,已经逐步替代传统的散热材料,成为新一代电子封装材料。近年来,价格不断下降的人造金刚石和铜这种相对价格低廉的金属结合,实现人们对电子封装材料性能优越、成本可控的要求。介绍了金刚石/铜复合材料的主要制备方法以及如何改善与提高这类材料的热导率。然而,对于当前工业化的迅猛发展以及5G时代的到来,如何实现高热导率的金刚石/铜复合材料的大规模工业生产,仍然是一个挑战。     

Experimental Study of Machinability in Millgrinding of SiCp/Al Composites

An attempt was made to investigate the machinability of Si Cp/Al composites based on the experimental study using mill-grinding processing method. The experiments were carried out on a high-speed CNC machining center using integrated abrasive cutting tool. The effects of combined machining parameters, e g, cutting speed(vs), feed rate(vf), and depth of cut(ap), with the same change of material removal rate(MRR) on the mill-grinding force and surface roughness(Ra) were investigated. The formation mechanism of typical machined surface defects was analyzed by SEM. The experimental results reveal that with the same change of material removal rate, lower mill-grinding force values can be gained by increasing depth of cut and feed rate simultaneously at higher cutting speed. With the same change of MRR value, lower surface roughness values can be gained by increasing the feed rate at higher cutting speed, rather than just increasing the depth of cut, or increasing the feed rate and depth of cut simultaneously. The machined surface of Si Cp/Al composites reveals typical defects which can influence surface integrity.     

Microstructure and properties of electronic packaging shell with high silicon carbide aluminum-base composites by semi-solid thixoforming

The electronic packaging shell with high silicon carbide aluminum-base composites was prepared by semi-solid thixoforming technique. The flow characteristic of the Si C particulate was analyzed. The microstructures of different parts of the shell were observed by scanning electron microscopy and optical microscopy, and the thermophysical and mechanical properties of the shell were tested. The results show that there exists the segregation phenomenon between the Si C particulate and the liquid phase during thixoforming, the liquid phase flows from the shell, and the Si C particles accumulate at the bottom of the shell. The volume fraction of Si C decreases gradually from the bottom to the walls. Accordingly, the thermal conductivities of bottom center and walls are 178 and 164 W·m-1·K-1, the coefficients of thermal expansion（CTE） are 8.2×10-6 and 12.6×10-6 K-1, respectively. The flexural strength decreases slightly from 437 to 347 MPa. The microstructures and properties of the shell show gradient distribution.     

Spark Plasma Sintered AIN-BN Composites and Its Thermal Conductivity

A series of samples of hexagonal boron nitride-aluminum nitride ceramic composites with different amounts of CaF2 as sintering aid were prepared by spark plasma sintered at 1700-1850 ℃ for 5 min.The addition of CaF2 effectively lowered the sintering temperature and promoted the densification of AlN-BN composites.With the increase of sintering temperature,the density increased,and the contiguity of AIN grains enhanced in AIN-BN composites.Thermal conductivity of AIN-BN composites increased with the increase in CaF2 content and sintering temat 1800 ℃.     

Thermal expansion and mechanical properties of middle reinforcement content SiCp/Al composites fabricated by PM technology

Middle reinforcement content SiCp/Al composites(Vp=30%, 35% and 40%) for precision optical systems applications were fabricated by powder metallurgy technology. The composites were free of porosity and SiC particles distributed uniformly in the composites. The mean linear coefficients of thermal expansion(20-100 ℃) of SiCp/Al composites ranged from 11.6×10-6 to 13.3×10-6 K-1 and decreased with an increase in volume fraction of SiC content. The experimental coeffi cients of thermal expansion agreed well with predicted values based on Kerner's model. The Brinell hardness increased from 116 to 147, and the modulus increased from 99 to 112 GPa for the corresponding composites. The tensile strengths were higher than 320 MPa, but no signifi cant increasing trend between tensile strength and SiC content was observed.     

冷却速度对SiCp/2024Al热残余应力影响的数值模拟

针对冷却速度对SiCp／2024Al复合材料热残余应力的影响，通过复合材料显微组织观察，根据复合材料的形貌特征，建立了平面应力状态的复合材料组织模型，利用有限元方法对SiCp／2024Al复合材料淬火和退火过程的热应力进行了数值模拟．结果表明，由于SiC增强颗粒与铝基体之间的热膨胀系数差异较大，热处理后颗粒和基体的界面附近产生很大的热残余应力场，同时基体发生塑性应变；冷却速度对复合材料热残余应力没有明显影响．