Metal injection molding of W-Ni-Fe microcutters

2011 ◽  
Vol 31 (4) ◽  
Author(s):  
Ming-Shyan Huang ◽  
Chin-Feng Chung

Abstract This investigation applies metal injection molding (MIM) to fabricate precise microcutters from W-Ni-Fe alloy powder. The hard and brittle W-Ni-Fe alloy is difficult to machine, and MIM must be applied to produce near net-shaped products. MIM involves the injection molding of feedstock by blending metal powder and binders, debinding, and sintering. Liquid-phase sintering is commonly adopted to improve the density and mechanical properties of the sintered parts, but it is inferior in terms of dimensional stability. This study elucidates the dimensional stability of sintered parts made from W-Ni-Fe alloy feedstocks that contain 83 and 93 wt% W. The powder injection molding of microcutters that demand micrometer-scale precision is considered as an example. The Taguchi method is utilized to optimize injection molding and sintering parameters, effectively optimizing the dimensional stability and mechanical properties. Experimental results show that (1) feedstock with 93 wt% W exhibited little and consistent shrinkage (25%–26%); (2) the optimal injection molding parameters determined by the Taguchi method yield an eccentricity of over 18%, and (3) in the sintering process, low heating rate significantly improves dimensional stability. The average hardness of microcutters, sintered at various heating rates, ranges from Vickers hardness 446 to 452.

2020 ◽  
Author(s):  
Fatma Hentati ◽  
Neila Masmoudi

This study optimized the influence of process parameters on the mechanical properties during injection molding (IM) of PC/ABS blend. The Taguchi method of design of experiments (DOE) was employed to optimize the process parameters and to increase the tensile strength and the elasticity module. Taguchi’s L9 (34) orthogonal array design was employed for the experimental plan. Process parameters of the injection molding such as material temperature, injection pressure, holding time, and mold temperature were studied with three levels. The Signal to noise (S/N) ratio for mechanical properties of PC/ABS blend using the Taguchi method was calculated. Taguchi’s results proposed two sets of optimal injection parameters conditions to achieve the best mechanical characteristics (σ, E). The (S/N) ratio results proved that the injection pressure was the more prominent than the other IM process parameters for the tensile strength, and the material temperature was the more prominent for the elasticity module.


2010 ◽  
Vol 39 (5) ◽  
pp. 775-780 ◽  
Author(s):  
Hu Youhua ◽  
Li Yimin ◽  
He Hao ◽  
Lou Jia ◽  
Tang Xiao

2011 ◽  
Vol 52-54 ◽  
pp. 244-248
Author(s):  
Haw Pei Li ◽  
Norhamidi Muhamad ◽  
Abu Bakar Sulong ◽  
Heng Shye Yunn ◽  
Hooman Abolhasani

Optimization of injection parameters in Micro Metal Injection Molding (μMIM) was described in this study. Stainless steel powder was mixed with Polyethelena Glycol (PEG), Polymethyl Methacrilate (PMMA) and Cellulose Acetate Butyrate (CAB) to produce feedstock. Design of Experiments (DOE) of Taguchi L-27 (313) orthogonal array technique has been used to investigate the significance and optimal injection molding parameters. The signal-to-noise ratio and analysis of variance (ANOVA) are applied to study the optimum levels and effects of process parameters. Simultaneous optimization to obtain the highest green density and excellent surface appearance was discussed. The result concluded that the mold temperature (D) is the most statistically significant process parameter and its contribution to the best appearance and density is the highest.


2021 ◽  
Vol 1028 ◽  
pp. 403-408
Author(s):  
Apang Djafar Shieddieque ◽  
Shinta Virdhian ◽  
Moch Iqbal Zaelana Muttahar ◽  
Muhammad Rafi Muttaqin

Metal injection molding (MIM) is a near net shape manufacturing technique for producing small, complex, precision parts in mass production. MIM process is manufacturing method that combines traditional shape-making capability of plastic injection molding and the materials flexibility of powder metallurgy. The process consists of the following four steps: mixing of metal powder and binder, injection molding to shape the component, debinding to remove the binder in the component, sintering to consolidate the debound parts. In this research, the physical and mechanical properties of metal injection molded 17-4 PH stainless steel were investigated with the variation of sintering temperatures (1300 °C - 1360 °C) and atmosphere conditions (argon and vacuum conditions). The relative density, microstructure, distortion, and hardness are measured and analyzed in this study. The results show that highest relative density of 87%, relative homogeneous shrinkage and high hardness are achieved by sintering at 1360 °C for 1.5 hours and argon atmosphere. At the same sintering temperature and time, sintering in vacuum shows lower relative density (81%) than that in argon condition due to pores growth. The pore growths were not observed in the argon atmosphere. It can be concluded that sintering stages more rapidly under vacuum condition. The hardness measurements result also showed that high hardness is obtained by high density parts. The optimum average hardness obtained in this study is 239 HV. However, the hardness properties results are still lower than 280 HV according to MPIF Standard 35 for MIM parts.


2007 ◽  
Vol 26-28 ◽  
pp. 355-358
Author(s):  
Chang Kyu Kim ◽  
Chang Young Son ◽  
Dae Jin Ha ◽  
Tae Sik Yoon ◽  
Sung Hak Lee

Powder injection molding (PIM) process was applied to Fe-based metamorphic alloy powders, and microstructure, hardness, and wear resistance of the PIM products were analyzed and compared with those of conventional PIM stainless steel products. When Fe-based metamorphic powders were injection-molded and then sintered at 1200 oC, completely densified products with almost no pores were obtained. They contained 34 vol.% of (Cr,Fe)2B borides dispersed in the austenitic matrix without amorphous phases. Since these (Cr,Fe)2B borides were very hard and thermally stable, hardness, and wear resistance of the PIM products of Fe-based metamorphic powders were twice as high as those of conventional PIM stainless steel products. Such property improvement suggested new applicability of the PIM products of Fe-based metamorphic powders to structures and parts requiring excellent mechanical properties.


2010 ◽  
Vol 443 ◽  
pp. 63-68 ◽  
Author(s):  
Khairur Rijal Jamaludin ◽  
Norhamidi Muhamad ◽  
Mohd Nizam Ab. Rahman ◽  
Sufizar Ahmad ◽  
Mohd Halim Irwan Ibrahim ◽  
...  

The Grey-Taguchi method was adopted in this study to optimize the injection molding parameters for the MIM green compacts with multiple quality performance. A Grey relational grade obtained from the Grey relational analysis is used as the quality performance in the Taguchi method. Then, the optimum injection molding parameters are determined using the parameter design proposed by the Taguchi method. The result concluded that the mold temperature (D) is very significant, by the fact that the ANOVA shows its contribution to excellent surface appearance as well as strong and dense green compacts is 38.82%.


2012 ◽  
Vol 602-604 ◽  
pp. 627-630 ◽  
Author(s):  
Kyu Sik Kim ◽  
Kee Ahn Lee ◽  
Jong Ha Kim ◽  
Si Woo Park ◽  
Kyu Sang Cho

Inconel 713C alloy was tried to manufacture by using MIM(Metal Injection Molding) process. The high-temperature mechanical properties of MIMed Inconel 713C were also investigated. Processing defects such as pores and binders could be observed near the surface. Tensile tests were conducted from room temperature to 900°C. The result of tensile tests showed that this alloy had similar or somewhat higher strengths (YS: 734 MPa, UTS: 968 MPa, elongation: 7.16 % at room temperature) from RT to 700°C than those of conventional Inconel 713C alloys. Above 800°C, however, ultimate tensile strength decreased rapidly with increasing temperature (lower than casted Inconel 713C). Based on the observation of fractography, initial crack was found to have started near the surface defects and propagated rapidly. The superior mechanical properties of MIMed Inconel 713C could be obtained by optimizing the MIM process parameters.


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