Sintering metal injection molding parts of tungsten-based steel using microwave and conventional heating methods

Abstract

In recent years, the near net shape metal injection molding process combines desirable features of plastic injection molding and powder metallurgy processes to gain high strength-to-weight ratio for manufacturing complex-shaped parts. The metal injection molding process consists of mixing, molding, debinding, and sintering. Microwave processing has attracted much attention in global research because of its unique features such as its ability to heat and sinter a wide variety of metals and its significant advantages in energy efficiency, processing speed, and compatibility. Also, it presents few environmental risks and can produce refined microstructures. The injected samples to be sintered are composed of fine tool steel metal powder and binders, stearic acid, paraffin wax, low-density polyethylene, and polyethylene glycol (600). In recent years, microwave-assisted post-treatment is considered a novel method for processing green parts. In this work, the green parts are subjected to high-intensity microwave fields which operate at a frequency of 2.45 GHz. Metal injection molding compacts were sintered using multi-mode microwave radiation. The sintering of a metal injection molding compact by microwaves has hardly been reported. The metal injection molding compact showed better results than those produced by sintering with conventional heating. This study evaluates the effect of conventional sintering and microwave sintering on mechanical properties. By optimizing the sintering process, increased sintered hardness, a more homogeneous microstructure, and greater shrinkage were obtained using microwave-assisted sintering.

Improving die tooling properties by spraying TiC-Ti-Al and TiB2-Ti-Al electro-explosive coatings

“…There is the effect of increasing the durability of equipment after each repair, which leads to an even greater economic effect [22]. A group of Indian scientists led by Veeresh Nayak C [23][24][25] are studying various materials obtained by injection molding, as well as sintered materials, by the microwave method. The aim of this work is the formation of TiC-Ti-Al and TiB 2 -Ti-Al coatings by electric-explosive spraying method and subsequent electron-beam treatment, as well as the study of their structure, phase composition, wear resistance, friction coefficient and microhardness.…”