Failure analysis of brass rotor bars

被引：4

作者：

Chen, CK ^{[1
]}

Lin, CY ^{[1
]}

机构：

[1] Met Ind Res & Dev Ctr, Met Forming Technol Sect, Kaohsiung 811, Taiwan

来源：

ENGINEERING FAILURE ANALYSIS | 2001年 / 8卷 / 03期

关键词：

intergranular fracture; cracks; residual stress; grain size; thermal stress;

D O I：

10.1016/S1350-6307(00)00004-2

中图分类号：

TH [机械、仪表工业];

学科分类号：

0802 ;

摘要：

Cracked rotor bars with characteristic chemical composition of 90Cu-10Zn are investigated in this paper. A brazing technique was employed to join these rotor bars with rings in a motor assembly factory. However, frequent edge cracks were observed after this joining process. Intergranular facets of these cracked bars revealed brittle fracture. Mechanical tests of the bars showed lack of ductility and strength, and the bars were found to have a higher lead (Pb) content. In addition, the season cracking susceptibility of copper alloy that can result in intergranular brittle fracture was assessed. The metallurgical structure revealed a very large grain size (150 mum) in the copper alloy. Non-uniform thermal stresses in the heating process triggered cracking of the bars owing to an insufficiency of material strength. The large grain size accounted for the failures. (C) 2001 Elsevier Science Ltd. All rights reserved.

引用

页码：293 / 301

页数：9