scholarly journals Effects of Bonding Treatment and Ball Milling on W-20 wt.% Cu Composite Powder for Injection Molding

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1897
Author(s):  
Mingliang Ouyang ◽  
Cuiping Wang ◽  
Huayu Zhang ◽  
Xingjun Liu
Keyword(s):  
Injection Molding ◽  
Ball Milling ◽  
Composite Powder ◽  
Hydrogen Gas ◽  
Powder Injection ◽  
Small Particles ◽  
Tap Density ◽  
Large Particles ◽  
Dimension Precision ◽  
Powder Characteristics

W-20 wt.% Cu pseudo-alloys were produced via powder injection molding (PIM) with powders prepared thermochemically. Bonding treatment and ball milling (BTBM) were used, and the effects of BTBM on the characteristics of the powders, rheological properties of the feedstock, shrinkage and properties of the sintered samples were studied. The morphology of the powder changed from extremely agglomerated small particles to pebble-shaped smooth large particles which were composed of several small particles combined tightly. The tap density increased from 3.25 g/cm3 to 7.22 g/cm3, and the specific surface area decreased from 0.86 m2/g to 0.45 m2/g. The critical powder loading of the feedstock increased from 45 vol.% to 56 vol.% due to the change in powder characteristics, thereby improving densification and dimension precision. For the PIM samples sintered at 1290 °C for 120 min in a hydrogen gas, the oversizing factor decreased from 1.297 to 1.216, and the dimension fluctuation ratio decreased from ±0.61% to ±0.33%. At the same time, the relative density increased from 97.8% to 98.6%, the thermal conductivity increased from 218 W/(m·K) to 233 W/(m·K), and the average coefficients of thermal expansion were roughly similar, within the range of 8.43–8.52 × 10−6/K.

Effect of Dry and Wet Ball Milling Process on Critical Powder Loading and Mixture Properties of Fine WC-10Co-0.8VC Powder

2012 ◽  
Vol 59 (2) ◽  
Author(s):  
Abdolali Fayyaz ◽  
Norhamidi Muhamad ◽  
Abu Bakar Sulong ◽  
Heng Shye Yunn ◽  
Sri Yulis M. Amin ◽  
...  
Keyword(s):  
Injection Molding ◽  
Tungsten Carbide ◽  
Ball Milling ◽  
Powder Mixture ◽  
Milling Process ◽  
Powder Injection Molding ◽  
Variation Method ◽  
Powder Injection ◽  
Solid Loading ◽  
Wet Milling

Micro powder injection molding (μPIM) has great potential for the production of micro cemented carbide parts that require high hardness and toughness. The main stages of the μPIM process include mixing the powder and organic binder, injecting, debinding, and sintering. High critical solid loading of submicron tungsten carbide (WC) powder is one of the requirements in the micro powder injection molding process, which is not obtained easily. This paper investigates the effects of ball milling on critical solid loading of submicron WC. Dry and wet ball milling processes were used to prepare a powder mixture with composition of WC-10Co-0.8VC (wt-%). Critical powder volume concentration (CPVC) was determined using the torque variation method, and the powder characteristics were assessed using scanning electron microscopy and energy dispersive X-ray spectroscopy. CPVC was at 42% and 50% for the dry and wet ball milling processes, respectively. Apparent and tap densities of the powder mixture were achieved at 2.4 g/cm3 and 2.96 g/cm3 after dry milling and at 2.54 g/cm3 and 3.39 g/cm3 after wet milling, respectively. Wet ball milling causes fine particles to de-agglomerate and improves the critical solid loading, which is advantageous for submicron cemented tungsten carbide injection molding. The homogeneity of the powder mixture can improve under longer time of wet milling process and it can be expected that reduce microstructure defects in sintered components.

Specific volume and features of compressibility during the molding of powder-polymer mixtures with wax-polypropylene binder

2019 ◽  
pp. 25-33
Author(s):  
Alexander Muranov ◽  
Alexey Semenov ◽  
Anatoly Kutsbakh ◽  
Boris Semenov
Keyword(s):  
Phase Transition ◽  
Comparative Analysis ◽  
Powder Metallurgy ◽  
Injection Molding ◽  
Polymer Binder ◽  
Polymer Mixture ◽  
Powder Injection ◽  
Polymer Mixtures ◽  
Pvt Data ◽  
Mathematical Processing

The article discusses one of the modern areas of powder metallurgy – the technology of manufacturing shaped parts by the powder injection molding (PIM). For the powder-polymer mixture (feedstock) with a wax-polypropylene binder of the solvent-thermal type of removal by isobaric volume dilatometry, the dependence of PVT state parameters was studied. For each component of the polymer binder, the dependence of pressure on the temperature of phase transition was obtained. As a result of mathematical processing and analysis of PVT data for the feedstock of the studied type, a technological window of parameters has been determined that allows injection molding of «green parts» with minimal volume shrinkage. The results of a comparative analysis of the compaction of feedstock with a polymer binder catalytic and solution-thermal type of removal are presented.

scholarly journals Preparation of the Composite Powder Al – B4C by Ball Milling for Cold Spray

2021 ◽  
Vol 1945 (1) ◽  
pp. 012033
Author(s):  
A E Chesnokov ◽  
A V Smirnov ◽  
S V Klinkov ◽  
V F Kosarev
Keyword(s):  
Ball Milling ◽  
Cold Spray ◽  
Composite Powder

Ti-6Al-4V alloy bimodal powders for powder injection molding

2020 ◽  
Author(s):  
Elena Glazkova ◽  
Nikolay Rodkevich ◽  
Nikita Toropkov ◽  
Aleksandr Pervikov ◽  
Marat Lerner
Keyword(s):  
Injection Molding ◽  
Powder Injection Molding ◽  
Powder Injection
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