本文選題：真空霧化 + Cu-Cr(Fe)合金　； 參考：《西安理工大學(xué)》2017年碩士論文

【摘要】：本課題使真空霧化的Cu-Cr合金粉末作為制備Cu-Cr合金的基本粉末,通過熱壓燒結(jié)獲得Cu-Cr合金材料,可大幅度降低合金中Cr的尺寸,從而提高Cu-Cr合金的綜合性能。研究了不同霧化工藝、霧化參數(shù)下合金粉末的粒徑分布及表面形貌,確定了制備Cu-Cr合金粉末的最佳工藝及參數(shù):并分析了 Cr含量的提高對Cu-Cr合金粉末組織和性能的影響及不同冷速合金中Cr的形貌變化規(guī)律:研究了不同成分Cu-Cr合金燒結(jié)樣及時效處理后的組織與性能的變化;探究第三組元Fe的加入對合金組織與性能的影響。所得實驗結(jié)果如下;(1)真空霧化制備的Cu-Cr合金粉末具有更高的球形度,粉末基本為規(guī)則的球形顆粒,含有極少量的異形粉,且粉末的氧含量極低。制備Cu-Cr合金粉末的最佳的霧化參數(shù)為:霧化漏嘴粒4mm、霧化壓力5MPa、過熱度150℃。在該霧化參數(shù)下獲得粉末的細粉收得率高、粉末粒徑分布范圍窄、粉末為規(guī)則的球形顆粒。(2)隨著合金中Cr含量的提高, Cu-Cr合金粉末組織中的初生Cr相逐漸增多,初生Cr相尺寸維持在11μm。在本實驗條件下,真空霧化法將Cu-Cr合金粉末中Cr的固溶度提高至3.26wt%。隨冷速的提高,Cu-Cr合金中Cr的形貌由長度約為5μm的棒條狀向球形顆粒轉(zhuǎn)變。當冷速達到1O5K/s時,Cr完全固溶進Cu基體中形成Cu-Cr共晶組織。(3)不同成分Cu-Cr合金粉末熱壓燒結(jié)后,合金的致密度隨Cr含量的提高呈下降趨勢。當Cu-Cr合金中的Cr含量超過2.5wt%時,在基體中出現(xiàn)了球狀的初生Cr相并隨Cr含量的增加而增多,初生Cr相的尺寸約為1μm,比常規(guī)鑄造法制備的Cu-Cr中Cr的尺寸縮小10倍左右。(4) Cu-Cr合金燒結(jié)樣品的導(dǎo)電率隨Cr含量的增加而降低,硬度隨Cr含量增加而升高。合金中的Cr含量從2.5wt%增加到4wt%時,導(dǎo)電率從86.5%IACS降低到73.4% IACS,硬度從61,5HB增加73.2HB。合金成分為Cu-3Cr時,使用熱壓燒結(jié)法比常規(guī)鑄造法所合金的硬度提高了 13HB,導(dǎo)電率提高了29.2%IACS Cu-4Cr合金在500℃時效2h后綜合性能最優(yōu),硬度增加到82HB,導(dǎo)電率提高至77.8%IACS。(5)Cu-Cr合金中加入第三組元Fe降低了Cr在Cu中的固溶度,使Cu-2.5Cr-0.5Fe合金粉末組織中出現(xiàn)了少量的初生Cr相,同時大量的Cr沿晶界析出。相比Cu-3Cr合金,Cu-2.5Cr-0.5Fe合金燒結(jié)樣硬度提高到78.2HB,導(dǎo)電率下降至65.4%IACS。
[Abstract]:In this paper, the vacuum atomized Cu-Cr alloy powder is used as the basic powder for the preparation of Cu-Cr alloy. The Cu-Cr alloy material can be obtained by hot pressing sintering, which can greatly reduce the size of Cr in the alloy and improve the comprehensive properties of the Cu-Cr alloy. The particle size distribution and surface morphology of alloy powder under different atomization process and atomization parameters were studied. The optimum process and parameters for preparing Cu-Cr alloy powder were determined. The effect of Cr content on the microstructure and properties of Cu-Cr alloy powder and the variation rule of Cr morphology in different cold speed alloy were analyzed. Changes of microstructure and properties of gold sintered samples and aging treatment; The effect of the addition of the third element Fe on the microstructure and properties of the alloy was investigated. The experimental results are as follows: (1) the Cu-Cr alloy powder prepared by vacuum atomization has a higher spherical degree, the powder is basically a regular spherical particle, contains a very small amount of special-shaped powder, and the oxygen content of the powder is very low. The optimum atomization parameters for the preparation of Cu-Cr alloy powder are as follows: atomizing leakage particle 4mm, atomizing pressure 5MPa, superheat degree 150 鈩，

本文編號：2011214