The Effect of Particles Shape and Size on Feedstock Flowibility and Chemical content of As-sintered NiTi Alloys

3rd International Conference on Global Sustainability and Chemical Engineering

工业技术;化学工业

Abdul Kadir, R.A.^1 ; Razali, R.^2 ; Mohamad Nor, N.H.^1 ; Subuki, I.^2 ; Ismail, M.H.^1

Centre for Advanced Materials Research (CAMAR), Faculty of Mechanical Engineering, University Teknologi Mara, Selangor, Shah Alam

40450, Malaysia^1

Faculty of Chemical Engineering, University Teknologi Mara, Shah Alam, Selangor

40450, Malaysia^2

关键词: Capillary rheometer;    Comparative studies;    Composite binders;    High vacuum furnaces;    Impurity content;    Metal injection moulding;    Shear-thinning behavior;    Sintering process;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/358/1/012064/pdf
DOI  :  10.1088/1757-899X/358/1/012064

学科分类：工业工程学

来源: IOP

【 摘 要 】

This paper presents a comparative study of two different titanium powders in fabrication of NiTi alloys by metal injection moulding (MIM) route. Two batches of powder mixture consisted of Ni-Ti and Ni-TiH2 with atomic ratio (at%) of 50-50 were prepared. TiH2 powder was used as a substitution for pure Ti powder owing to its relatively cheaper cost and has been claimed favourable in producing less impurity uptake in sintering process. The binder system used for both mixtures comprised of composite binder of palm stearin (PS) and polyethylene (PE) at weigth ratio (wt%) of 60-40. The flow behaviour of the mixtures was analysed using a capillary rheometer at different shear rates and temperatures. The results showed that owing to irregular shape of TiH2 compared to Ti powder, the viscosity of the feedstock was significantly higher, thus required greater temperature in order to improve the mouldability of the feedstock. Nevertheless, both feedstocks exhibited pseudoplastic, a shear thinning behavior with shear rate and temperature, desirable properties for injection moulding process. Samples prepared with Ni-Ti feedstock were sintered in a high vacuum furnace, while Ni-TiH2 feedstock was sintered in a tube furnace under a flowing of Argon gas. The results showed that the impurity contents (Carbon and Oxygen) for both feedstocks were almost comparable, suggesting NiTi alloy samples prepared with TiH2 powder is an attractive route for manufacturing of NiTi alloys.