Assessment of Microwave Heating for Sintering of Al/SiC and for in‐situ Synthesis of TiC

Abstract

This work describes sintering of SiC‐reinforced Al‐matrix composites and in‐situ synthesis of TiC in a powder mixture of Ti and C. In the first case, microwave energy is absorbed by SiC grains, heating the metal matrix to sintering and even melting temperature. The composite is processed at <1 kW microwave power. Microwave absorption and the heating rate increase with decreasing SiC particle size. Composites with high SiC content (70 vol.‐%) are processed at 650 °C/1 h in the microwave furnace, whereas conventional resistive heating at the same temperature did not allow sintering of the sample. In the second case, radiative energy allowed the heating of Ti/C samples up to 950 °C, and microwave assistance enhanced the reaction sintering of Ti/C powder mixtures forming TiC at the border of the Ti particles. The results are compared with conventional processing. Optical images and XRD patterns confirmed the formation of TiC for both techniques.

Experimental and theoretical investigation on microwave melting of metals

“…Microwave sintering of metal-matrix composites such as copper-graphite composites was performed and the resulting finer microstructure enhanced the performance of the composites (Rajkumar and Aravindan, 2009). Sintering of other metal-matrix composites such as Al/SiC, Ti/C were achieved at high temperatures (>933 K) with low input power (<1 kW) using microwaves (Leparoux et al, 2003). Successful microwave brazing of nickel-titanium alloy has also been reported (Eijk et al, 2008).…”

Effect of Bottom Ash and Fly Ash as a Susceptor Material on The Properties of Aluminium Based Composites Prepared by Microwave Sintering

“…In Figure 5, the microstructure is smooth and less pores. The presence of pores in the sample is related to microwave sintering technique which depend on the heating rate used in the microwave oven [7]. It is proved that the heating rate during microwave sintering is better when used fly ash as the susceptor.…”

“…This was led to volumetric heating of samples with short duration. [7] 3.2. Microstructure observation Figure 4 and Figure 5 show the microstructure of aluminium based composites sintered by microwave sintering using bottom ash susceptor and fly ash susceptor, respectively.…”

Enhancing the Mechanical Response of a Lead-Free Solder Using an Energy-Efficient Microwave Sintering Route

“…Sintering can be done by traditional methods of heating such as resistance heating 6,7 or by the more recently introduced method of using microwaves. [8][9][10][11][12][13][14][15][16] In a typical resistance heating furnace, the direction of heating is from the outside to the inside of the powder compact, while for microwaves the direction of heating is from the inside to the outside. The former results in poor microstructural characteristics in the core of the powder compact while the latter results in poor microstructural characteristics of the surface.…”