Anomalous corrosion phenomena observed on electrovalves of coffee espresso machines

被引：1

作者：

Barella, Silvia ^{[1
]}

Gruttadauria, Andrea ^{[1
]}

Mapelli, Carlo ^{[1
]}

Mombelli, Davide ^{[1
]}

机构：

[1] Politecn Milan, Dipartimento Meccan, I-20156 Milan, Italy

来源：

ENGINEERING FAILURE ANALYSIS | 2013年 / 33卷

关键词：

Domestic coffee machines; Electra-pump; Crevice; Galvanic coupling; Iron-manganese bacteria; STEEL;

D O I：

10.1016/j.engfailanal.2013.06.025

中图分类号：

TH [机械、仪表工业];

学科分类号：

0802 ;

摘要：

The domestic coffee machines market has widely expanded in the last five years. The core of these machines is an electro-pump that allows the correct water distribution. In this paper a root cause failure analysis was conducted utilizing some electro-pumps samples taken from a corroded batch. Several examinations were carried out in order to identify the root cause of the failure: visual examination, SEM-EDS analysis and microstructural characterization. The corrosion phenomenon is located at the piston-spring interface. As result of the examinations carried out, it has been possible to identify that the corrosion mechanism is due to different interacting factors: high chlorine concentration, potential dynamic difference between piston and spring materials, material sensitization and iron-manganese bacteria growth. (C) 2013 Elsevier Ltd. All rights reserved.

引用

页码：449 / 456

页数：8