硅、铈、锑和锡对块状石墨形成的影响

摘要

用电解铁,高纯硅,石墨,纯铈,锑和锡制成含有不同硅、铈、锑和锡含量,且C%+l/3 Si%=4.45%的13种母合金.每种合金用高纯度氧化铝坩埚在1 450℃,氩气保护下的电炉中重熔,然后在30 K/min速率下冷却,获得冷却曲线.用光学显微镜和扫描电镜观察它们的石墨形貌.为了讨论硅和铈含量对块状石墨形成的影响,进行了试验.在第一个试验中,变化了0.15%硅铈合金中的硅含量从0到4%;在第二个试验中,使用了含有0.1%和0.2%不同铈量的3.5%和4%硅的试样.在第三个试验中,使用了含铈0.1%,含硅4%的试样,研究了锑和锡对块状石墨形成的影响.试验结果表明,硅含量大于3.0%,块状石墨的体积分数会增加.随后讨论了不同含量的硅和铈对块状石墨形成的影响.不能确定3.5%和4.0%的硅量差对块状石墨形成的差别,证实了含有0.2%铈的样品中块状石墨的体积分数大于0.1%铈的试样.由于高硅含量,还不能确定锑和锡的加入对防止块状石墨形成的作用,还需要做进一步的研究.%The thirteen mother alloys, C％ +1/3Si％ =4.45％, differing in their Si, Ce, Sb and Sn contents, were prepared using electrolytic iron, high purity Si and graphite, pure Ce, Sb and Sn.Seventy grams of these alloys was remelted in a high purity alumina crucible at 1 450 ℃ under an Ar atmosphere, then cooled at 30 K/min for obtaining their cooling curves. Their graphite morphologies were observed using an optical microscope, and an SEM. For discussing the influence of the Si and Ce contents on the chunky graphite formation, experiments were carried out. In the first one, we changed the Si contents from 0 to 4％ in the 0.15％Ce alloys, and for the second one,we used the 3.5％ and 4％Si samples that differed in the Ce contents of 0.1％ and 0.2％. In the third experiment, the influence of Sb and Sn on the chunky graphite formation was investigated using the 4％Si and 0.1％Ce samples. If the Si content is greater than 3.0％, the volume fraction of the chunky graphite increases. We then discussed the interaction between the Si and Ce contents on the chunky graphite formation. The difference in the Si contents, 3.5％ and 4.0％, on the chunky graphite formation can not be confirmed, nevertheless, we confirmed that the chunky graphite volume fraction in the 0.2％Ce samples is higher than that of the 0.1％Ce samples. The effect of the Sb and Sn additions on the prevention of chunky graphite formation can not be confirmed due to their high Si contents. Therefore, we need further studies in this field.