排序方式: 共有26条查询结果,搜索用时 78 毫秒
1.
2.
3.
Fe38Ni30Si16B14V2 amorphous composite coatings were fabricated by laser cladding on AISI 1045 steel in order to increase the wear resistance. The phase and microstructure of the coatings were analyzed by X-ray diffractometry and transmission electron microscopy. The wear properties of the coatings were also investigated by means of sliding wear test. The results show that the coating consists of amorphous phase in majority and nanocrystalline phase in minority. The amorphous coatings can be obtained while the scanning speed is 3 500 mm/min and the laser power is 4.8 kW. With increase of the laser power, the amorphous phase in the coating increases when it is lower than 4.8 kW. A gradient distribution of the microhardness ranges from Hv0.2 1 208 to Hv0.2 891 in the coating from top surface of the coating to the substrate. The amorphous coating is found to possess better property of wear than AISI 1045 steel substrate. 相似文献
5.
对以激光熔覆方式在45钢基体上制备的FeNiSiBVRE非晶涂层进行激光晶化,制备非晶/纳米晶复合涂层,利用X射线衍射仪、透射电镜、扫描电镜和磨损试验机研究非晶/纳米晶复合涂层的组织与性能,研究结果表明,涂层存在着分层结构,组成相有晶化相、非晶相和纳米晶相;涂层底部和顶部的显微组织由大量的稀土树枝晶、板条状硼化物和粒状碳化物组成,涂层中部的显微组织是由大量的纳米晶相镶嵌在非晶基体上构成,与没有进行激光晶化的非晶涂层相比,涂层的耐磨损性能下降,其磨损机制以粘着磨损和剥层磨损为主。 相似文献
6.
7.
8.
研究了稀土RE微合金化对激光熔覆Fe38Ni30Si16B14V2(原子分数,%)非晶复合涂层的影响.使用X射线衍射和扫描电镜分析熔覆层物相、组织结构与RE对非晶相形成的影响.结果表明,激光熔覆条件下,稀土RE的微合金化能提高Fe38Ni30Si16B14V2合金的玻璃形成能力,有利于形成非晶涂层.稀土RE的加入改变了非晶合金的结晶体系,稀土RE加入量为1时促进γ-Fe, Ni相的结晶,抑制Fe2B相的结晶;RE为2时,两种相的结晶均受到抑制.稀土RE的微合金化使涂层的显微硬度值降低,涂层的显微硬度沿涂层厚度方向下降. 相似文献
9.
针对汉语连续语音,本文提出了采用径向基函数神经网络(RBFNNs),对基于输出的语音质量进行客观评价的一种新方法——RBFOBSQ(Output-Based Speech Quality Using RBFNNs).该方法采用Mel倒谱对语音系统输出端的待测语音信号进行特征参数提取,然后通过RBF神经网络完成特征参数到主观评价MOS分的非线性映射,其映射值即为仅依赖于输出的客观音质评价结果,其与主观评价MOS分的相关度,当采用训练集样本时达到0.92以上,而采用测试集样本时达到0.88以上. 相似文献
10.