Improving the homogeneity and properties of ferrous powder mixes by a novel powder mixing process

ABSTRACT

Fe-2Cu-0.8C powder mixes were prepared by a wet mixing and spray-drying process using iron, copper, graphite and zinc stearate as main raw materials, and stearic acid, alcohol wax and amide wax as binders. The properties of the as-prepared binder treated powder mixes were investigated. The bonding efficiency of the binders was tested by measure the retention of graphite and copper in the powder mixes after dusting resistance test. The test results show that the wet mixing and spray-drying process can realise the bonding of different particles and improve processing properties of the powder mixes. A flow rate of 30.6 s/50 g and an apparent density of 3.18 g/cm³ were obtained for powder mixes with alcohol wax as binder. The results of dusting resistance test demonstrated that alcohol wax and amide wax have better bonding effect for Cu and graphite powders, respectively, which was reflected by the difference value of electronegativity between Fe, Cu, C elements and functional groups. Compared with mechanically mixing powder mixes, using binder treated powder mixes can also reduce the friction coefficient during compaction by 0.012–0.026. The addition of different binders also has a great influence on the properties of sintered parts.

KEYWORDS:

• Ferrous powders
• powder mixing
• binders
• processing properties
• functional group

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes on contributors

Wenchao Chen was born in 1988 and is a doctoral candidate. His research interests includes high performance iron-based powder metallurgy materials and application research.

Jigui Cheng is a professor. His research interest is advanced powder metallurgy technologies and materials.

Lu Cheng is a master graduate. Her research interest is high performance powder metallurgy materials.

Pengqi Chen is a lecture. His research interest includes preparation of superfine powders and PM materials.

Jiabin Xu is a master candidate. His research interest is high wear resistance powder metallurgy materials.

ORCID

Pengqi Chen http://orcid.org/0000-0002-6416-3779