热处理对激光粉末床熔合Cu-Cr-Zr合金组织、力学性能和导电性的影响
<p style="text-align:left"><br/></p><p><strong><span style="font-size:16px;font-family:宋体">导读</span></strong></p><p><span style="font-size:16px;font-family:宋体">铜铬锆合金是一种沉淀强化铜合金,该合金在时效处理后可以通过析出颗粒进行强化。因其优异的导电性和良好的机械强度广泛应用于电子材料领域。近年来,由于对复杂结构铜件的需求有所增加,传统制造加工工艺在制造复杂形状部件方面面临着很大的挑战。激光粉末床熔合</span><span style="font-size:16px;font-family:'Times New Roman',serif">(Laser powder bed fusion, LPBF)</span><span style="font-size:16px;font-family:宋体">是一种利用高能激光束将金属粉末熔化在每层相应位置,逐层叠加制造三维固体零件的新兴技术。与传统制造加工技术相比,该技术具有能够制造复杂几何形状零件的独特优势。因此,将</span><span style="font-size:16px;font-family:'Times New Roman',serif">LPBF</span><span style="font-size:16px;font-family:宋体">技术应用于复杂结构铜合金零件的制造受到了广泛的关注。然而,现有的关于</span><span style="font-size:16px;font-family:'Times New Roman',serif">Cu-Cr-Zr</span><span style="font-size:16px;font-family:宋体">合金的研究大多集中在力学性能的表征上,研究合金导电性调控的报道较少。近日,暨南大学先进耐磨蚀及功能材料研究院周吉强、佟鑫、王小健等人为揭示铜合金热处理工艺对机械性能和导电性调控的内在机理。首先通过</span><span style="font-size:16px;font-family:'Times New Roman',serif">L-PBF</span><span style="font-size:16px;font-family:宋体">工艺优化确定较优的</span><span style="font-size:16px;font-family:'Times New Roman',serif">CuCrZr</span><span style="font-size:16px;font-family:宋体">合金成型工艺参数,并对成型样品做了系统的热处理研究,表征和测试了</span><span style="font-size:16px;font-family:'Times New Roman',serif">CuCrZr</span><span style="font-size:16px;font-family:宋体">合金在不同热处理条件下的显微组织、显微硬度、拉伸力学性能和导电性。相关研究以</span><span style="font-size:16px;font-family:'Times New Roman',serif">“Effect of heat treatments on microstructure, mechanical and electrical properties of Cu–Cr–Zr alloy manufactured by laser powder bed fusion”</span><span style="font-size:16px;font-family:宋体">为题,发表在《</span><span style="font-size:16px;font-family:'Times New Roman',serif">Materials Chemistry and Physics</span><span style="font-size:16px;font-family:宋体">》上。</span></p><p style="text-align:left"><br/></p><p style="text-align:left"><strong><span style="font-size:16px;font-family:宋体"><br/></span></strong></p><p style="text-align:left"><strong><span style="font-size:16px;font-family:宋体">研究要点</span></strong></p><p style="text-align:left"><span style="font-size:16px;font-family:宋体"><br/> </span></p><p style="text-align:left;text-indent:32px"><span style="font-size:16px;font-family:'Times New Roman',serif;letter-spacing: 1px">1</span><span style="font-size:16px;font-family: 宋体;letter-spacing:1px">、</span><span style="font-size:16px;font-family:'Times New Roman',serif;letter-spacing:1px">CuCrZr</span><span style="font-size:16px;font-family:宋体;letter-spacing: 1px">合金</span><span style="font-size:16px;font-family:'Times New Roman',serif;letter-spacing: 1px">LPBF</span><span style="font-size:16px;font-family: 宋体;letter-spacing:1px">成型工艺优化</span></p><p style="text-align:left;text-indent:32px"><span style="font-size:16px;font-family:宋体">通过调节工艺参数,对铜合金打印参数进行筛选优化,对成型试样相对密度结果进行统计,结果表明,所有试样相对密度均大于</span><span style="font-size:16px;font-family:'Times New Roman',serif">98.4%</span><span style="font-size:16px;font-family:宋体">。最终优选出激光功率</span><span style="font-size:16px;font-family: 'Times New Roman',serif">370W</span><span style="font-size:16px;font-family:宋体">,扫描速度</span><span style="font-size:16px;font-family:'Times New Roman',serif">800mm/s</span><span style="font-size:16px;font-family:宋体">,扫描间距</span><span style="font-size:16px;font-family:'Times New Roman',serif">90μm</span><span style="font-size:16px;font-family:宋体">,铺粉层厚</span><span style="font-size:16px;font-family:'Times New Roman',serif">30μm</span><span style="font-size:16px;font-family:宋体">作为试验样品的制备工艺,在此工艺组合下成型样品的相对密度为</span><span style="font-size: 16px;font-family:'Times New Roman',serif">99.26±0.05%</span><span style="font-size:16px;font-family:宋体">,根据样品的横纵截面金相图,可以看出几乎没有孔洞等缺陷的存在。</span></p><p style="text-align:center"><span style="font-size:16px;font-family:宋体"> <img src="upfiles/a8f896201d3ad5fa4.jpg" border="0"/> </span></p><p style="text-align:left"><span style="font-size:16px;font-family:宋体">图</span><span style="font-size:16px;font-family:'Times New Roman',serif">1 (a)</span><span style="font-size:16px;font-family:宋体">不同工艺参数下样品的相对密度</span><span style="font-size:16px;font-family: 'Times New Roman',serif">(</span><span style="font-size:16px;font-family:宋体">相对于</span><span style="font-size:16px;font-family:'Times New Roman',serif">Cu-Cr-Zr</span><span style="font-size:16px;font-family:宋体">密度为</span><span style="font-size:16px;font-family:'Times New Roman',serif">8.95 g cm<sup>−3</sup>)</span><span style="font-size:16px;font-family:宋体">,</span><span style="font-size:16px;font-family:'Times New Roman',serif">(b) XOY</span><span style="font-size:16px;font-family:宋体">构筑面</span><span style="font-size:16px;font-family:'Times New Roman',serif">OM</span><span style="font-size:16px;font-family:宋体">图像,</span><span style="font-size:16px;font-family:'Times New Roman',serif">(c) XOZ</span><span style="font-size:16px;font-family:宋体">构筑面</span><span style="font-size:16px;font-family:'Times New Roman',serif">OM</span><span style="font-size:16px;font-family:宋体">图像</span></p><p style="text-align:left"><span style="font-size:16px;font-family:'Times New Roman',serif">2</span><span style="font-size:16px;font-family:宋体">、</span><span style="font-size:16px;font-family:'Times New Roman',serif">LPBF</span><span style="font-size:16px;font-family:宋体">成型</span><span style="font-size:16px;font-family:'Times New Roman',serif">CuCrZr</span><span style="font-size:16px;font-family:宋体">合金的显微结构表征根据对不同截面的显微结构分析,表明在</span><span style="font-size:16px;font-family:'Times New Roman',serif">XOY</span><span style="font-size:16px;font-family: 宋体">平面具有更加明显的择优取向。而在</span><span style="font-size:16px;font-family:'Times New Roman',serif">XOZ</span><span style="font-size:16px;font-family:宋体">平面没有观察到晶粒的择优取向,除了晶粒取向不同外,不同平面上的晶粒形态也不同。在</span><span style="font-size:16px;font-family:'Times New Roman',serif">XOY</span><span style="font-size:16px;font-family: 宋体">平面上观察到大量的拉长晶粒,一些较小的晶粒位于熔体轨迹中心,晶粒在熔体轨迹边界处发生弯曲。而在</span><span style="font-size:16px;font-family:'Times New Roman',serif">XOZ</span><span style="font-size:16px;font-family:宋体">面上可以发现大量沿成形方向伸长的晶粒通过对比</span><span style="font-size:16px;font-family:'Times New Roman',serif">IPF</span><span style="font-size:16px;font-family:宋体">图中并没有观察到明显的熔池形貌,说明熔池内外的晶体学取向没有明显变化。</span></p><p style="text-align:left"><span style="font-size: 16px; font-family: " times="" new=""><img src="upfiles/a80b7ec1f8cb986ac.jpg" border="0"/></span></p><p style="text-align:left"><span style="font-size: 16px; font-family: " times="" new="">图2 </span><span style="font-size: 16px; font-family: 宋体;">不同截面的典型</span><span style="font-size: 16px; font-family: " times="" new="">EBSD</span><span style="font-size: 16px; font-family: 宋体;">结果</span><span style="font-size: 16px; font-family: " times="" new="">:(a) BD (XOY</span><span style="font-size: 16px; font-family: 宋体;">平面</span><span style="font-size: 16px; font-family: " times="" new="">)</span><span style="font-size: 16px; font-family: 宋体;">,</span><span style="font-size: 16px; font-family: " times="" new="">(b) TD (XOZ</span><span style="font-size: 16px; font-family: 宋体;">平面</span><span style="font-size: 16px; font-family: " times="" new="">)</span></p><p style="text-align:left"><span style="font-size: 16px; font-family: 宋体;"><img src="upfiles/a0275476b03babcc1.jpg" border="0"/></span></p><p style="text-align:left"><span style="font-size: 16px; font-family: 宋体;">图</span><span style="font-size: 16px; font-family: " times="" new="">3 LPBF Cu-Cr-Zr</span><span style="font-size: 16px; font-family: 宋体;">合金的显微组织分析</span><span style="font-size: 16px; font-family: " times="" new="">:(a) XOY</span><span style="font-size: 16px; font-family: 宋体;">面晶粒特征,</span><span style="font-size: 16px; font-family: " times="" new="">(b</span><span style="font-size: 16px; font-family: 宋体;">、</span><span style="font-size: 16px; font-family: " times="" new=""> c) </span><span style="font-size: 16px; font-family: 宋体;">两个不同形貌区域</span><span style="font-size: 16px; font-family: " times="" new="">(</span><span style="font-size: 16px; font-family: 宋体;">标记为</span><span style="font-size: 16px; font-family: " times="" new="">a</span><span style="font-size: 16px; font-family: 宋体;">和</span><span style="font-size: 16px; font-family: " times="" new="">b)</span><span style="font-size: 16px; font-family: 宋体;">,</span><span style="font-size: 16px; font-family: " times="" new=""> (d)</span><span style="font-size: 16px; font-family: 宋体;">纳米析出相和位错,</span><span style="font-size: 16px; font-family: " times="" new="">(e) XOZ</span><span style="font-size: 16px; font-family: 宋体;">面晶粒特征,</span><span style="font-size: 16px; font-family: " times="" new="">(f)</span><span style="font-size: 16px; font-family: 宋体;">熔池晶粒生长特征,</span><span style="font-size: 16px; font-family: " times="" new="">(g ~ h)</span><span style="font-size: 16px; font-family: 宋体;">晶粒外延生长</span></p><p style="text-align:left"><span style="font-size: 16px; font-family: 宋体;"><br/></span></p><p style="text-align:left;text-indent:32px"><span style="font-size:16px;font-family:宋体">3</span><span style="font-size:16px;font-family:宋体;letter-spacing:1px">、</span><span style="font-size:16px;font-family:'Times New Roman',serif;letter-spacing:1px">Cu-Cr-Zr</span><span style="font-size:16px;font-family:宋体;letter-spacing: 1px">合金热处理前后组织的比较</span></p><p style="text-align:left"><span style="font-size:16px;font-family:宋体">通过观察热处理前后的显微组织变化,在</span><span style="font-size:16px;font-family:'Times New Roman',serif">XOZ</span><span style="font-size:16px;font-family:宋体">平面可观察到熔池形貌,</span><span style="font-size: 16px;font-family:'Times New Roman',serif">SA</span><span style="font-size:16px;font-family:宋体">处理后的熔池形貌轨迹消失,且晶粒边界存在大量球状析出相,通过对析出相进行表征,球状析出相主要成分为纯</span><span style="font-size:16px;font-family:'Times New Roman',serif">Cr</span><span style="font-size:16px;font-family:宋体">,主要在晶粒边界处密集分布。</span></p><p style="text-align:left"><img src="upfiles/aa4b3f2a5add8011c.jpg" border="0"/></p><p style="text-align:left"><span style="font-size:16px;font-family:宋体">图</span><span style="font-size:16px;font-family:'Times New Roman',serif">4 <span style="color: black;letter-spacing:1px">LPBF</span></span><span style="font-size:16px;font-family:宋体;color:black;letter-spacing:1px">热处理前和热处理后的显微形貌</span><span style="font-size: 16px;font-family:'Times New Roman',serif;color:black;letter-spacing:1px">(ST-950◦C-30min, DA-475◦C-2h</span><span style="font-size:16px;font-family:宋体;color:black;letter-spacing:1px">,和</span><span style="font-size:16px;font-family:'Times New Roman',serif;color:black;letter-spacing:1px">DA-600◦C-2h)</span></p><p style="text-align:left"><img src="upfiles/ab11800917d943ecf.jpg" border="0"/></p><p style="text-align:left"><span style="font-size:16px;font-family:宋体">图</span><span style="font-size:16px;font-family:'Times New Roman',serif">5 ST-950◦C-30min</span><span style="font-size:16px;font-family:宋体">样品</span><span style="font-size:16px;font-family:'Times New Roman',serif">EDS</span><span style="font-size:16px;font-family:宋体">分析</span><span style="font-size:16px;font-family:'Times New Roman',serif"> (a) XOY</span><span style="font-size:16px;font-family:宋体">平面和</span><span style="font-size:16px;font-family:'Times New Roman',serif">(b) XOZ</span><span style="font-size:16px;font-family:宋体">平面</span></p><p style="text-align:left"><span style="font-size:16px;font-family:'Times New Roman',serif">4</span><span style="font-size:16px;font-family:宋体">、</span><span style="font-size:16px;font-family:宋体">机械性能和导电率</span><span style="font-size:16px;font-family:宋体;letter-spacing:1px">随着时效温度的升高,合金的抗拉强度先增大后减小,在</span><span style="font-size:16px;font-family:'Times New Roman',serif;letter-spacing:1px">DA-475◦C-2h(519.3±3.5 MPa)</span><span style="font-size:16px;font-family:宋体;letter-spacing:1px">处达到最大值,</span><span style="font-size:16px;font-family:'Times New Roman',serif;letter-spacing:1px">XOY</span><span style="font-size:16px;font-family:宋体;letter-spacing:1px">平面与</span><span style="font-size:16px;font-family:'Times New Roman',serif;letter-spacing:1px">XOZ</span><span style="font-size: 16px;font-family:宋体;letter-spacing: 1px">平面试样的显微硬度值没有明显差异。不同建筑平面热处理后试样显微硬度的变化与抗拉强度的变化基本一致。与其他报道的合金的力学性能和电导率相比,目前的</span><span style="font-size:16px;font-family:'Times New Roman',serif;letter-spacing:1px">Cu-Cr-Zr</span><span style="font-size:16px;font-family:宋体;letter-spacing:1px">合金</span><span style="font-size:16px;font-family:'Times New Roman',serif;letter-spacing:1px">(DA- 475◦C-2h)</span><span style="font-size:16px;font-family:宋体;letter-spacing:1px">表现出优异的力学性能和电导率组合</span><span style="font-size:16px;font-family:'Times New Roman',serif;letter-spacing:1px">(</span><span style="font-size:16px;font-family:宋体;letter-spacing:1px">高屈服强度和高电导率</span><span style="font-size:16px;font-family:'Times New Roman',serif;letter-spacing:1px">)</span><span style="font-size: 16px;font-family:宋体;letter-spacing: 1px">。结果显示,经过时效处理后,</span><span style="font-size:16px;font-family:'Times New Roman',serif;letter-spacing:1px">Cu-Cr-Zr</span><span style="font-size:16px;font-family:宋体;letter-spacing:1px">合金的力学性能和电导率均有显著提高。</span></p><p style="text-align:left"><img src="upfiles/a36e73c0f9d2906d7.jpg" border="0"/></p><p style="text-align:left"><span style="font-size:16px;font-family:宋体">图</span><span style="font-size:16px;font-family:'Times New Roman',serif">6 </span><span style="font-size:16px;font-family:宋体">热处理前后的应力</span><span style="font-size:16px;font-family:'Times New Roman',serif">-</span><span style="font-size:16px;font-family:宋体">应变曲线</span></p><p style="text-align:left"><img src="upfiles/a3b29eae45789c58d.jpg" border="0"/></p><p style="text-align:left"><span style="font-size:16px;font-family:宋体">图</span><span style="font-size:16px;font-family:黑体">7</span><span style="font-size:16px;font-family:'Calibri',sans-serif"> </span><span style="font-size:16px;font-family: 宋体">热处理前后拉伸力学性能及显微硬度变化<span style="letter-spacing:1px">。</span></span></p><p style="text-align:left"><img src="upfiles/a26ee022b875f0b62.jpg" border="0"/></p><p style="text-align:left"><span style="font-size:16px;font-family:宋体">图</span><span style="font-size:16px;font-family:'Times New Roman',serif">8 </span><span style="font-size:16px;font-family:宋体;color:black;letter-spacing:1px">直接时效处理对</span><span style="font-size:16px;font-family:'Times New Roman',serif;color:black;letter-spacing:1px">LPBF Cu-Cr-Zr</span><span style="font-size:16px;font-family:宋体;color:black;letter-spacing:1px">合金电导率的影响</span></p><p style="text-align:left"><span style="font-size:16px;font-family:'Times New Roman',serif">5.</span><span style="font-size:16px;font-family:宋体">强化机理</span><span style="font-size:16px;font-family:'Times New Roman',serif">Cu-Cr-Zr</span><span style="font-size:16px;font-family:宋体">合金是一种沉淀强化合金。时效处理使固溶体原子</span><span style="font-size:16px;font-family:'Times New Roman',serif">(Cr)</span><span style="font-size:16px;font-family:宋体">在纳米尺度上析出。时效温度越高,固溶原子</span><span style="font-size:16px;font-family:'Times New Roman',serif">(Cr)</span><span style="font-size:16px;font-family: 宋体">析出越充分,固溶强化、位错强化和晶界强化对合金的强化有一定的作用。不同热处理工艺后,计算屈服强度与实测屈服强度一致,在</span><span style="font-size:16px;font-family:'Times New Roman',serif">DA-475◦C-2h</span><span style="font-size:16px;font-family:宋体">和</span><span style="font-size:16px;font-family:'Times New Roman',serif">DA-600◦C-2h</span><span style="font-size:16px;font-family:宋体">样品中,主要的强化机制是沉淀强化,分别占总强化的</span><span style="font-size:16px;font-family:'Times New Roman',serif">89.6%</span><span style="font-size:16px;font-family:宋体">和</span><span style="font-size:16px;font-family:'Times New Roman',serif">82.4%</span><span style="font-size:16px;font-family:宋体">。</span><span style="font-size:16px;font-family:'Times New Roman',serif">DA-475◦C-2h</span><span style="font-size:16px;font-family:宋体">与</span><span style="font-size:16px;font-family:'Times New Roman',serif">DA-600◦C-2h</span><span style="font-size:16px;font-family:宋体">之间强度值的显著差异主要是由沉淀强化控制的。</span></p><p style="text-align:left"><img src="upfiles/a7fe4fa89f168d532.jpg" border="0"/></p><p style="text-align:left"><span style="font-size:16px;font-family:宋体;color:black;letter-spacing:1px">图</span><span style="font-size:16px;font-family:'Times New Roman',serif;color:black;letter-spacing:1px">9 LPBF Cu-Cr-Zr</span><span style="font-size:16px;font-family:宋体;color:black;letter-spacing:1px">合金</span><span style="font-size:16px;font-family:'Times New Roman',serif;color:black;letter-spacing:1px">KAM</span><span style="font-size:16px;font-family:宋体;color:black;letter-spacing:1px">分析</span><span style="font-size:16px;font-family:'Times New Roman',serif;color:black;letter-spacing:1px"> (a, b) XOY</span><span style="font-size:16px;font-family:宋体;color:black;letter-spacing:1px">面,</span><span style="font-size:16px;font-family:'Times New Roman',serif;color:black;letter-spacing:1px">(c, d) XOZ</span><span style="font-size:16px;font-family:宋体;color:black;letter-spacing:1px">面</span></p><p style="text-align:left"><img src="upfiles/a250f097e8c58024b.png" border="0"/></p><p style="text-align:left"><span style="font-size:16px;font-family:宋体">图</span><span style="font-size:16px;font-family:'Times New Roman',serif">10 Cu-Cr-Zr</span><span style="font-size:16px;font-family:宋体">合金理论屈服强度与实测屈服强度比较图</span></p><p style="text-align:left"><strong><span style="font-size:16px;font-family:宋体;letter-spacing: 0">总结:</span></strong><span style="font-size: 16px;font-family:宋体"><br/> </span><span style="font-size:16px;font-family:宋体">该研究通过优化工艺参数获得致密度较高的铜合金成型试样,通过时效处理显著提高</span><span style="font-size:16px;font-family:'Times New Roman',serif">Cu-Cr-Zr</span><span style="font-size:16px;font-family:宋体">合金的力学性能和电导率,通过强化机理分析,表明,富</span><span style="font-size:16px;font-family:'Times New Roman',serif">cr</span><span style="font-size:16px;font-family:宋体">相的析出是提高合金机械强度和电导率的主要原因。本工作的开展能够为当前铜合金性能研究提供实质性的参考价值。</span></p><p style="text-align:left;text-indent:32px"><span style="font-size:16px;font-family:宋体">原文信息:</span></p><p style="text-align:left"><span style=";font-family:'Times New Roman',serif">ZHOU J, HUANG Y, LI Z, et al. Effect of heat treatments on microstructure, mechanical and electrical properties of Cu–Cr–Zr alloy manufactured by laser powder bed fusion [J]. Materials Chemistry and Physics, 2023, 296: 127249.</span></p><p style="text-align:left;text-indent:32px"><span style="font-size:16px;font-family:宋体;letter-spacing:1px">原文链接:</span></p><p style="text-align:left"><span style="font-size:16px;font-family:'Times New Roman',serif">https://doi.org/10.1016/j.matchemphys.2022.127249</span></p>