摘要W-Cu复合材料既具有 W 强度高、耐高温的优点,又具有 Cu 导热性延展性好的优点,被广泛应用于航空航天、电子、机械等领域。本文研究了 W-Cu 复合材料的激光熔覆快速成形。通过调整 W、Cu 配比,研究其对组织性能的影响,并通过添加 Ni、Co 来促进烧结致密化。利用 XRD、SEM 、EDS 方法观察 W-Cu 复合材料的组织结构、成分及相组成,同时测定其相对致密度和显微硬度,并分析了相关作用机制。实验结果表明:当 Cu≥60wt.%时,发生“钨包铜”现象;而当 Cu 含量降低到 20wt.%时,产生较多孔洞。当Ni≥30wt.%时,出现γ-Ni 相;Co 可以固溶于Cu 相中,增强 W 原子在 Cu 中的扩散。两者都能较大幅度地提高 W-Cu复合材料的致密度,且相比之下 Co的作用更加显著。 26719
毕业论文关键词 W-Cu复合材料 激光熔覆 颗粒分布 相对密度
Title Laser Cladding Rapid Protyping Technology for W-Cu Composites and the Study for Its Properties
Abstract
Due to the combination of high strength and good heat resistance of W and high
electrical and thermal conductivity of Cu ,tungsten-copper (W-Cu) composites have
been widely used in aerospace, electronics, machinery and other areas. In this
paper, the laser cladding rapid prototyping for W-Cu composites has been studied.
The influence of the mass ratio of W and Cu on the structure and properties were
investigated .In addition, Ni/Co were added to the W-Cu composites to promote the
sintering densification. The effects of the elements on the structure, phase
composition, relative density and hardness of W-Cu composites were investigated
by using XRD, SEM, EDS, the relative density and hardness test .The relative
mechanism was also analyzed in this paper. The results showed that: When the content
of Cu≥60wt%, the W-rim and Cu-core structure occurred; When it reduced to 20wt.%,
the number of pores will increase. When the content of Ni≥3.0wt.%, γ -Ni phase
can be observed; Co can be dissolved in the Cu phase and enhance the diffusion
of W in Cu phase. Both Ni and Co can increase the density of the W-Cu composites
greatly, and Co is more effective in comparison.
Keywords W-Cu composites Laser Cladding Particle distribution Relative density
目 次
1 引言 1
1.1 W-Cu复合材料 .. 1
1.1.1 W-Cu复合材料的性能 .. 1
1.1.2 W-Cu复合材料的传统制备方法 . 2
1.1.3 钨铜复合材料的发展前景及难题 3
1.2 激光熔覆快速成形 3
1.2.1 激光熔覆 . 3
1.2.2 快速原型 . 4
1.2.3 激光熔覆快速成形 5
1.3 本章总结 .. 10
2 实验步骤 .. 11
2.1 粉末制备 .. 11
2.2 基底处理 .. 12
2.3 激光加工 .. 12
2.4 性能测试 .. 13
2.4.1 金相分析(OM) .. 13
2.4.2 致密度测定 . 14
2.4.3 扫描电镜观察(SEM)及能谱分析(EDS) .. 15
2.4.5 物相分析(XRD) 15
2.4.6 显微硬度测试 15
3 实验结果及分析 .. 16
3.1 W-Cu复合材料的组织结构及性能 . 16
3.1.1 粉末形貌 .. 16
3.1.2 截面形貌 .. 16
3.1.3 截面元素分布 19 W-Cu复合材料的激光熔覆快速成形及其性能研究:http://www.751com.cn/cailiao/lunwen_20984.html