镁钙黄铜组织及性能的研究

Study on the Microstructure and Properties of Mg-Ca Brass

利用OM、SEM、EDS、XRD等分析手段对镁钙黄铜组织性能进行研究,结果表明,少量的镁钙细化黄铜晶粒组织。增加镁钙含量,晶粒组织变得粗大;合金由α相和β相双相变为α相、β相和Cu2Mg、Ca Cu四相,受第二相粒子的影响,切屑先变小后变大,硬度逐渐增加,电导率逐渐减小。镁钙黄铜为脱锌腐蚀,腐蚀前期,合金元素可优先占据阳极锌溶解产生的双空位,阻碍锌的扩散,提高耐蚀性;但镁钙的腐蚀电位低,其含量的增加,易形成微电池腐蚀,降低合金耐蚀性。综合本试验得出含0.61%镁钙的黄铜组织性能最佳。

The microstructure and properties of Mg-Ca brass was studied by OM, SEM, EDS and XRD analysis method. The results show that the grain size of brass is refined first and then tends to be bulky with the increase of Mg-Ca. The alloy obtains Cu2 Mg and Ca Cu phases besides alpha and beta matrix phases. Influenced by the increase of second-phase particles, the cuttings size is decreased first and then increased. At the same time hardness is increased but conductivity is decreased accordingly. The Mg-Ca brass is dezincification corrosion.The divacancy produced by zinc as anodic dissolution could be occupied by alloy elements preferentially in the early stage of corrosion. So the diffusion of zinc is put off and the corrosion resistance is improved. But the corrosion potentials of calcium and magnesium are low, so the micro cell corrosion is easy to form and reduces the alloy corrosion resistance. This test indicated that the microstructure and properties of brass with 0.61%Mg-Ca is best.