本文選題：Cu-Ni-Si-Cr-Zr合金 + 時(shí)效處理　； 參考：《南昌航空大學(xué)》2015年碩士論文

【摘要】：電阻點(diǎn)焊是薄板連接的一種重要工藝方法。點(diǎn)焊電極是整個(gè)點(diǎn)焊過程中最易損耗的材料之一。隨著點(diǎn)焊技術(shù)應(yīng)用于鍍鋅鋼板、高強(qiáng)鋁合金連接領(lǐng)域,電極失效問題更為突出,研制長壽命電極材料勢(shì)在必行。本文在不同成分Cu-Ni-Si合金中添加Cr、Zr、B元素,通過合金化法制備了Cu-2.8Ni-0.7Si-0.6Cr-0.15Zr(WNi/Si=4:1)、Cu-2.8Ni-0.7Si-0.6Cr-0.15Zr-0.06B(WNi/Si=4:1)、Cu-2.8Ni-0.9Si-0.6Cr-0.15Zr(WNi/Si㩳4:1)、Cu-2.8Ni-0.56Si-0.6Cr-0.15Zr(WNi/Si㧐4:1)、Cu-0.6Cr-0.15Zr共5個(gè)成分的合金。系統(tǒng)研究了合金成分配比及不同熱處理工藝對(duì)合金導(dǎo)電性及力學(xué)性能的影響。主要研究?jī)?nèi)容及結(jié)論如下:1.Cu-Ni-Si-Cr-Zr合金鑄態(tài)組織主要由粗大的柱狀晶組成,在基體內(nèi)部彌散分布著大量的粗大過剩相。同時(shí)Ni、Si、B元素的引入細(xì)化了Cu-0.6Cr-0.15Zr合金鑄態(tài)組織,使其硬度提升的同時(shí)降低了合金導(dǎo)電率。2.對(duì)合金進(jìn)行固溶處理表明:隨固溶溫度的升高,晶粒長大趨勢(shì)明顯,同時(shí)導(dǎo)電率和硬度都快速下降,導(dǎo)電率最低值為16.03%IACS,硬度最低值為94.7HV。3.分析Cu-Ni-Si-Cr-Zr合金時(shí)效態(tài)成分組成與分布,發(fā)現(xiàn)基體中固溶了大量的Ni元素及少量的Si元素。而基體中的析出相顆粒主要富集在晶界處,其成分主要包括CrSi、CuZr、NiSi、B等,顆粒的主要形態(tài)有長條形,橢圓形以及圓盤狀。4.Cu-Ni-Si-Cr-Zr合金經(jīng)時(shí)效處理后,其導(dǎo)電率和硬度都能都得較大的回升。時(shí)效初期,Cu-Ni-Si-Cr-Zr合金導(dǎo)電率快速上升,且溫度越高,導(dǎo)電率到達(dá)峰值時(shí)間越短。隨著時(shí)效時(shí)間延長,導(dǎo)電率上升減緩,最后趨于平穩(wěn);對(duì)于合金硬度,在450℃和500℃時(shí)效時(shí),硬度快速攀升,到后期同樣趨于平穩(wěn),而在550℃時(shí)效初期,合金就已經(jīng)發(fā)生了過時(shí)效現(xiàn)象,硬度呈現(xiàn)下降趨勢(shì)。5.在時(shí)效態(tài)Cu-Ni-Si-Cr-Zr合金中,合金導(dǎo)電率峰值排序?yàn)?%IACS(Ni/Si=4:1)%IACS(Ni/Si=4:1,0.06B)%IACS(Ni/Si4:1)%IACS(Ni/Si4:1);合金硬度峰值排序?yàn)?HV(Ni/Si4:1)HV(Ni/Si=4:1,0.06B)HV(Ni/Si=4:1)HV(Ni/Si4:1)。合金成分對(duì)導(dǎo)電率的峰值影響有限,在4-9%IACS,而合金成分對(duì)硬度峰值的影響,在20-30HV之間。6.本文制備的合金有著良好的抗高溫軟化性能,合金硬度隨溫度的上升而下降,當(dāng)溫度上升到550℃-600℃區(qū)間時(shí),合金硬度出現(xiàn)大幅下降,各合金軟化溫度都在550℃以上,其中Cu-2.8Ni-0.7Si-0.6Cr-0.15Zr合金軟化溫度最高,為601℃。
[Abstract]:Resistance spot welding is an important process for sheet metal joining. Spot welding electrode is one of the most easily worn materials in the whole spot welding process. With the application of spot welding technology in galvanized steel sheet and high strength aluminum alloy connection, the problem of electrode failure becomes more serious, so it is imperative to develop long life electrode material. In this paper, Cu-2.8Ni-0.7Si-0.6Cr-0.15Cr-0.15Zr-WNiR / Si4: 1 alloy Cu-2.8Ni-0.7Si-0.6Cr-0.15Zr-0.06B / Si: 1Cu-2.8Ni-0.9Si-0.6Cr-0.15Zr-0.6Cr-0.15Zr-0.6Cr-0.15Zr-0.56Si-0.6Cr-0.15Cr-0.15Cr-0.15Cr-0.56Si-0.6Cr-0.15Zr alloy with 5 compositions was prepared by alloying method. The effects of alloy composition ratio and different heat treatment processes on the electrical conductivity and mechanical properties of the alloy were systematically studied. The main contents and conclusions are as follows: 1. The as-cast microstructure of Cu-Ni-Si-Cr-Zr alloy is mainly composed of coarse columnar crystals, and a large number of coarse excess phases are dispersed in the matrix. At the same time the microstructure of Cu-0.6Cr-0.15Zr alloy was refined by the introduction of NiOSi-B element, and the hardness of Cu-0.6Cr-0.15Zr alloy was increased and the conductivity of Cu-0.6Cr-0.15Zr alloy was decreased at the same time. The results of solution treatment show that with the increase of solution temperature, the grain length tends to be larger, the conductivity and hardness decrease rapidly, the lowest conductivity is 16.03 IACSs, and the lowest hardness is 94.7HV.3. The composition and distribution of aging state of Cu-Ni-Si-Cr-Zr alloy were analyzed. It was found that a large number of Ni elements and a small amount of Si elements were dissolved in the matrix. The precipitates in the matrix are mainly enriched at grain boundaries, and their compositions include CrSi-CuZr-NiSi-B and so on. The main morphology of the particles is long strip. After aging treatment, the conductivity and hardness of Cu-Ni-Si-Cr-Zr alloy can be increased greatly. The conductivity of Cu-Ni-Si-Cr-Zr alloy increases rapidly in the early aging period, and the higher the temperature, the shorter the time to reach the peak value. With the increase of aging time, the electrical conductivity increases slowly and finally tends to be stable. For alloy hardness, the hardness increases rapidly at 450 鈩，

本文編號(hào)：2032123