Metal Injection Molding of Nickel-Free Austenitic Stainless-Steels I-Manufacturing Process

2007 ◽  
Vol 26-28 ◽  
pp. 15-18
Author(s):  
Yoshikazu Kuroda ◽  
Midori Komada ◽  
Ryo Murakami ◽  
Shingo Fukumoto ◽  
Noriyuki Tsuchida ◽  
...  
Keyword(s):  
Injection Molding ◽  
Austenitic Stainless Steels ◽  
High Strength ◽  
Austenitic Steels ◽  
Metal Injection Molding ◽  
High Nitrogen ◽  
Molding Method ◽  
Combined Use ◽  
Work Hardening Rate ◽  
Near Net Shape

Ni-free austenitic steels containing high nitrogen have been developed to protect against earth resource. High nitrogen steels (HNS) have a lot of advantages, e.g., HNS have high strength, corrosion resistance, toughness, work hardening rate and large rocking parameter in the Hall-Petch equation. On the other hand, it is difficult to fabricate HNS by IM method under 0.1 MPa and to work at room temperature. We have tried to make HNS by combined use of metal injection molding method (MIM) and nitrogen absorption method. Powder compositions used was Fe-17Cr-12Mn-3Mo.The benefit of this method is to make metal parts in near net shape. In order to use this method, we should know the sintering heat schedule, timing for introducing nitrogen gas, gas pressure and setter material etc. Therefore, the shrinkage rate, density and the solution-treated microstructure of MIM compacts were examined to find out the optimum conditions.

Application of Physical Simulation for Developing New Steel Types

2008 ◽  
Vol 575-578 ◽  
pp. 1002-1007 ◽  
Author(s):  
L. Pentti Karjalainen ◽  
Mahesh C. Somani ◽  
Atef S. Hamada
Keyword(s):  
Mechanical Properties ◽  
Stainless Steels ◽  
Physical Simulation ◽  
Austenitic Stainless Steels ◽  
High Strength ◽  
Carbon Steels ◽  
Austenitic Steels ◽  
Low Carbon ◽  
Modelling Studies ◽  
Electron Microscopes

Processing of a large number of novel steel types, such as DP, TRIP, CP and TWIP, and high-strength low-carbon bainitic and martensitic DQ-T steels, have been developed based on physical simulation and modelling studies. Among stainless steels, guidelines for processing of ultra-fine grained austenitic stainless steels have been created. Physical simulation has been used by employing a Gleeble thermo-mechanical simulator to reveal the phenomena occurring in the hot rolling stage (the flow resistance, recrystallization kinetics and microstructure evolution), and in the cooling stage (CCT diagrams) for carbon steels and in short-term annealing of cold rolled metastable austenitic steels. Connecting these data with microstructures examined in optical and electron microscopes and resultant mechanical properties have improved the understanding on complex phenomena occurring in the processing of these steels and the role of numerous process variables in the optimization of enhanced mechanical properties.

Rheological Behavior of Carbon Nanotubes / Copper Feedstocks for Metal Injection Molding

2011 ◽  
Vol 403-408 ◽  
pp. 5335-5340 ◽  
Author(s):  
Faiz Ahmad ◽  
Ali Samer Muhsan ◽  
M. Rafi Raza
Keyword(s):  
Carbon Nanotubes ◽  
Injection Molding ◽  
Flow Behavior ◽  
Metal Injection Molding ◽  
Increasing Trend ◽  
Multi Walled Carbon Nanotubes ◽  
Blade Mixer ◽  
Near Net Shape ◽  
Copper Composite ◽  
Walled Carbon Nanotubes

Metal injection molding (MIM) technology is known for its ability of producing near net shape components. This study presents the results of flow behavior of multi-walled carbon nanotubes (MWCNTs) reinforced copper composites mixes. The solid loadings in the copper mixes were investigated in the ranges of 55-61 V% using a binder. Copper mixes and copper/MWCNTs were compounded using a Z-blade mixer for homogenous dispersion of solids in the binder. Results identified a mix containing 59 V% copper suitable for substitution of MWCNTs. The flow properties were measured using a capillary rheometer in the shear rate range expected to occur during metal injection molding. An increasing trend in viscosity of the copper mixes with powder loading was noted. Copper/MWCNTs composite mixes showed viscosity more than 1000 Pa.s perhaps due to addition of MWCNTs and increasing trend in viscosity of copper/MWECNTs was recorded. The results of flow data showed that all copper composite mix containing up to 10 Vol.% MWCNTs were successfully injection molding and test samples were produced.

Research Status and Developing of Metal Injection Molding

2012 ◽  
Vol 629 ◽  
pp. 100-104 ◽  
Author(s):  
Yi Qiang He ◽  
Bin Qiao ◽  
Jian Ming Yang ◽  
Li Chao Feng
Keyword(s):  
Injection Molding ◽  
Technical Characteristic ◽  
Metal Injection Molding ◽  
Full Potential ◽  
Matrix Composites ◽  
High Efficient ◽  
The Status ◽  
Near Net Shape ◽  
Viable Method ◽  
Mim Technology

Metal injection molding(MIM) is a high efficient and near net shape manufacturing technology, which is appropriate for parts of small size and complex shape. MIM provides a viable method to fabricate metal and metal matrix composites with discontinuous reinforcements, and micro metal injection molding (μMIM) is applied to manufacturing products at micro scale. The status of the research and development of MIM and μMIM are reviewed. Processes including mixing, injection molding and subsequent debinding and sintering are summarized. And technical characteristic, injection processing and application of μMIM are introduced. The disadvantages in mixing, injection molding and debinding processes limit MIM to fabricating components with small size, low precision and mechanical properties, and it is necessary to prevent the powder from reuniting and avoid any oxidation and impurity during μMIM process. Further investigations in these areas will give rise to being explored of full potential of MIM technology.

Metal Injection Molding Method of Ni-Free Austenitic Stainless Steel II - Microstructure and Mechanical Properties

2007 ◽  
Vol 26-28 ◽  
pp. 19-22
Author(s):  
Midori Komada ◽  
Yoshikazu Kuroda ◽  
Ryo Murakami ◽  
Noriyuki Tsuchida ◽  
Yasunori Harada ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Surface Layer ◽  
Injection Molding ◽  
Nitrogen Content ◽  
Tensile Tests ◽  
Metal Injection Molding ◽  
Homogeneous Microstructure ◽  
Molding Method ◽  
Microstructure And Mechanical Properties

Microstructure and mechanical properties of high nitrogen steels whose chemical composition were Fe-17Cr-12Mn-3Mo and that was produced by using metal injection molding method and nitrogen absorption methods were examined. A compact which is furnace cooled from 1573 K has a brittle surface layer with high chromium and nitrogen contents but the surface layer disappears when the compact is held at 1473 K. The compact which is furnace cooled at 1473 K is observed precipitates in the grains and the grain boundary, while the compact which is quenched at 1473 K shows homogeneous microstructure. In the heat treatments at 1473 K for 2, 5, and 10 h, the nitrogen content becomes higher with increasing of holding time. In the holding times of 5 and 10 h, the microstructure is austenite. In the tensile tests, tensile strength becomes larger with increasing of nitrogen content. In the specimen which is conducted the heat treatment at 1473 K for 10 h, tensile strength is about 1,000 MPa and elongation is 80 %, which shows better balance of strength and elongation than SUS304 and SUS316 steels.

Structure and Phase Transformations in High Nitrogen and High Interstitial Steels of Different Alloying Systems - Short Review

2021 ◽  
Vol 410 ◽  
pp. 167-172
Author(s):  
Vera V. Berezovskaya ◽  
Eugeny A. Merkushkin ◽  
Ksenia A. Mamchits
Keyword(s):  
Phase Transformations ◽  
Light And Electron Microscopy ◽  
Austenitic Stainless Steels ◽  
Short Review ◽  
Austenitic Steels ◽  
Structure Evolution ◽  
X Ray Diffraction ◽  
High Nitrogen ◽  
Corrosion Properties ◽  
Excess Phases

The features of the structure evolution under thermal effect of Cr, Cr-Ni, Cr-Ni-Mn, and Cr-Mn-austenitic stainless steels with high nitrogen content and a total high content of carbon and nitrogen are analyzed. When studying the structure, we used light and electron microscopy, X-ray diffraction, dilatometry analysis and electrical resistance measurements. Fine structure and aging processes of austenite, nature and morphology of excess phases, as well as character of phase transformations and their relationship with the properties of steels have been studied. It is shown that Cr-Mn-steels with a high content of (C + N), having a homogeneous structure of austenite without excess phases, surpass Cr-Ni austenitic steels in mechanical and corrosion properties, have higher process ability than Cr-Mn-N-steel and are comparable with them in mechanical properties.

Investigations on Metal Injection Molding of 316L SS Using Thermoplastic Natural Rubber (TPNR) Binder as a New System

2012 ◽  
Vol 576 ◽  
pp. 150-153 ◽  
Author(s):  
Hassan Norita ◽  
Noor Azlina Hassan ◽  
Sahrim H. Ahmad ◽  
N. Muhamad ◽  
Mohd Afian Omar ◽  
...  
Keyword(s):  
Solvent Extraction ◽  
Injection Molding ◽  
Natural Rubber ◽  
Extraction Process ◽  
Metal Injection Molding ◽  
Binder System ◽  
Outward Appearance ◽  
Injection Parameter ◽  
Near Net Shape ◽  
Thermoplastic Natural Rubber

Metal injection molding (MIM) is a near net-shape manufacturing technology that is capable of mass production of complex parts cost-effectively. The unique features of the process make it an attractive route for the fabrication of the new binder system since the success of MIM process is dependent on the outward appearance of the resultant feedstock. Thermoplastic natural rubbers (TPNR) blends consist of thermoplastics, such as polyethylene (PE), alloyed with natural rubber (NR) with different thermoplastic to NR ratios. The soft grade TPNR is produced by blends with compositions richer in rubber while the harder grades can contain up to about 30 % NR. This study investigates the influence of new binder system consisting of TPNR on injection parameter, density of injected molded specimen and changes during solvent extraction. Results show that TPNR plays an important role as a good binder system and shortens the solvent extraction process.

Laser Welded Joints of High-Nitrogen Austenitic Steels: Microstructure and Properties

2018 ◽  
Vol 284 ◽  
pp. 344-350 ◽  
Author(s):  
Vera V. Berezovskaya ◽  
A.V. Berezovskiy ◽  
D.H. Hilfi
Keyword(s):  
Welded Joints ◽  
Carbon Dioxide Laser ◽  
Continuous Wave ◽  
High Strength ◽  
Tensile Tests ◽  
Wave Mode ◽  
Austenitic Steels ◽  
Maximum Output ◽  
High Nitrogen ◽  
Corrosion Properties

High nitrogen austenitic steels are used as structural materials required possessing high strength and fracture toughness. The present study is concerned with the characteristic features (shape, size, properties and structure) of the laser welded joints in Cr-Mn-, Cr-Mn-Mo-high nitrogen steels compared to the ones of Cr-Ni-steel joint. Butt welded joints were made using carbon dioxide laser with a maximum output of 5 kW in the continuous wave mode. The hardness and tensile tests of welded joints in the air and 3.5 vol.%-solution of NaCl, as well as the theoretical studies were carried out by optical and transmission electron microscopy (TEM). The results are achieved by testing that the welded joints of HNS had satisfactory weldability, adequately high mechanical and corrosion properties. The austenite of the investigated HNS retains high stability throughout the welding cycle.

scholarly journals Development and Application of Rapid Injection Molds Using Aluminum-Filled Epoxy Resins for Metal Injection Molding

2021 ◽  
Author(s):  
Chil-Chyuan Kuo ◽  
Xin-Yu Pan ◽  
Cheng-Xuan Tasi
Keyword(s):  
Injection Molding ◽  
Epoxy Resins ◽  
Metal Injection Molding ◽  
Manufacturing Cost ◽  
Injection Mold ◽  
Rapid Injection ◽  
Near Net Shape ◽  
Tooling Technology ◽  
Manufacturing Time ◽  
Conventional Machining

Abstract Metal injection molding (MIM) is a near net-shape manufacturing process combing conventional plastic injection molding and powder metallurgy. Two kinds of injections molds for MIM were developed using conventional mold steel and aluminum (Al)-filled epoxy resins in this study. The characteristics of the mold made by rapid tooling technology (RTT) were evaluated and compared to that fabricated conventional machining method through MIM process. It was found that the service life of the injection mold fabricated by Al-filled epoxy resins is about 1300 molding cycles. The saving in manufacturing cost of an injection mold made by Al-filled epoxy resins is about 30.4% compared to that fabricated conventional mold steel. The saving in manufacturing time of an injection mold made by RT technology is about 30.3% compared to that fabricated conventional machining method.

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