Metal injection moulding of bronze using thermoplastic binder based on HDPE

Abstract

In the present work, the injection moulding process of a Cu-10Sn bronze has been studied. Different formulations of binders based on high density polyethylene, paraffin wax and polyethylene glycol have been used. The optimisation of the metallic load is based on torque measurements and rheological studies. The optimum powder loading was 60 vol.-%. The moulding parameters are selected to obtain homogeneous specimens with three different geometries and without distortions. The green parts have an adequate strength for handling. The organic binder was eliminated by thermal debinding under N 2 /10%H 2 atmosphere. The debinding process has been designed by means of thermogravimetrical analysis of binder and feedstock and considering the maximum heating rates at which the samples do not present cracks. The specimens were sintered at temperatures between 875 and 950uC in the same reducing atmosphere.

Powder injection moulding of premixed ferritic and austenitic stainless steel powders

“…Some characteristics of binder and pure components are shown in Table 3 (see Refs. [14,16] for further details).…”

“…High density polyethylene is a polymer commonly employed for plastic and powder injection moulding. In particular, we have successfully used a binder based on HDPE and paraffin wax as a second component for production of M2 and T15 high speed steels [14,15], bronze [16] and alumina [17] parts. PW is basically added to reduce the viscosity of binder.…”

Production of alumina parts by powder injection molding with a binder system based on high density polyethylene

“…In particular we have used binder based on HDPE and paraffin wax as a second component for the manufacturing of M2 high speed steels 14 and bronze parts. 15 The main advantages we have found using this binder system were good homogeneity of blends, suitable rheological features allowing easy moldability, and finally, and due to the different melting temperature of both binder component ensure that when one component has melted, the remaining component act as backbone retaining the shape of the parts. Despite these advantages, in the reviewed literature this polymer has not been previously reported for alumina injection molding.…”

Sintering optimisation and solution annealing of high nitrogen nickel free austenitic stainless steels prepared by PIM

“…The used binder was based on the thermoplastic polymers, consisted of 30 wt-% high density polyethylene, 65 wt-% paraffin wax and 5 wt-% stearic acid, and it has been used in the previous work. 14,15 The feedstock for injection moulding was prepared by mixing metal powder and binder in a LH60 Roller Mixer at 140uC for 1 h. The loading of metal powder was 62 vol.-%. The feedstock was injection moulded into an MPIF Standard 50 tensile bar cavity on a CJ80-E injection moulding machine.…”