*Communication* **Study of Coarse Particle Types, Structure and Crystallographic Orientation Relationships with Matrix in Cu-Cr-Zr-Ni-Si Alloy**

**Chengdong Xia 1, Chengyuan Ni 1, Yong Pang 1,\*, Yanlin Jia 2, Shaohui Deng <sup>1</sup> and Wenhui Zheng <sup>1</sup>**

<sup>1</sup> College of Mechanical Engineering, Quzhou University, Quzhou 324000, China; xcd309@163.com (C.X.)

<sup>2</sup> School of Materials Science and Engineering, Central South University, Changsha 410083, China

**\*** Correspondence: thgink@126.com

**Abstract:** Coarse particles in Cu-0.39Cr-0.24Zr-0.12Ni-0.027Si alloy were studied with scanning electron microscopy and transmission electron microscopy. Three types of coarse particles were determined: a needle-like Cu5Zr intermetallic phase, a nearly spherical Cr9.1Si0.9 intermetallic phase and (Cu, Cr, Zr, Ni, Si)-rich lath complex particles. The crystallographic orientation relationships of the needle-like and nearly spherical coarse particles were also determined. The reasons for formation and the role of the coarse phases in Cu-Cr-Zr alloys are discussed, and some suggestions are proposed to control the coarse phases in the alloys.

**Keywords:** Cu-Cr-Zr alloy; coarse particle; crystal structure; orientation relationship
