Influence of ball milling on powder characteristics and feedstock rheological behaviours of injection moulded ultrafine 98W–1Ni–1Fe

Abstract

In the present study, powder injection moulding (PIM) was used to fabricate ultrafine 98W–1Ni–1Fe preform. The influence of various ball milling times (3, 5 and 10 h) on the characteristics of the ultrafine powder and the rheological behaviour of the injection moulded feedstocks has been investigated over the 105–145°C temperature range and the 1·79–596·1 s⁻¹ shear range. The results show that all the feedstocks exhibit pseudoplastic flow behaviour. The increase in ball milling time could reduce the viscosity of the feedstock and enhance the shear stability by greatly diminishing the agglomeration of ultrafine particles. However, the powder ball milled for 5 h can produce a feedstock with better thermostability and comprehensive rheology. Therefore, compared with the powder ball milled for 3 and 10 h, the powder milled for 5 h is more suitable for ultrafine 98W–1Ni–1Fe PIM.

Keywords:

• Ultrafine 98W–1Ni–1Fe powder
• Ball milling
• Powder injection moulding
• Rheological behaviour

This research work is supported by the National Natural Science Foundation of China (grant no. 51074187), the National Natural Science Funds for Distinguished Young Scholars (grant no. 50925416) and the Creative Research Group of the National Nature Science Foundation of China (grant no. 51021063).