Effect of infra‐red power level on the sintering behaviour in the high speed sintering process

Abstract

PurposeTo investigate the effects of the infra‐red power level on sintering behaviour in the high speed sintering (HSS) process.Design/methodology/approachSingle‐layer parts were produced using the HSS process, in order to determine the effect of the infra‐red power level on the maximum achievable layer thickness, and the degree of sintering. The parts were examined using both optical microscopy and contact methods.FindingsIt was initially expected that an increase in the infra‐red lamp powder might allow an increase in the depth of sintering that could be achieved, as a result of increased thermal transfer through the powder. However, results in fact indicated that there is a maximum layer thickness that can be achieved, as a result of part shrinkage in the z direction. Optical microscopy images have shown that a greater degree of sintering occurs at higher power levels, which would be expected to correspond to an improvement in the mechanical properties of the parts produced. These images also indicate that the radiation absorbing material forms in small “islands” on the powder bed surface. As sintering progresses, these islands begin to merge; this occurs to a greater extent at higher infra‐red lamp powers.Research limitations/implicationsThese results are based only on single layer parts. Further work will examine the sintering characteristics of multiple layer parts.Practical implicationsResults have shown that, whilst it is not possible to increase the achievable layer thickness of the parts produced by modifying the infra‐red lamp power, the degree of sintering can be improved greatly by increasing the power.Originality/valueHSS is an entirely new process which is currently still under development; the results presented here will directly impact the direction of further development and research into this process.

Effect of Sintering Parameters and Flow Agent on the Mechanical Properties of High Speed Sintered Elastomer

“…A study by Ellis et al assessed the influence of print density on mechani cal properties of HSS nylon parts [6]. Other research concerning the HSS process include the study of excess powder hardness using nylon with HSS [7] and the effect of IR power level on sin tering behavior of Nylon-12 [8].…”

Effect of Various Infrared Heaters on Sintering Behavior of UHMWPE in Selective Inhibition Sintering Process

“…The sintered part precision and density of the parts highly influenced by the particle size of the powder and increasing crystallinity also lead to [13]. Researchers have also revealed that an increase in heater power [14], [15] up to certain level leads to increase in degree of sintering , but further increases leads to reducing in sintered part property due to degradation of power. B. Esakki, D. Rajamani and P. Arunkumar [8] have optimized the influences of four selected input parameters such as heater energy, printer feedrate, heater feedrate and layer thickness on the wear behavior of high-density polyethylene (HDPE) parts which were fabricated using SIS system.…”

Integration of additive manufacturing and inkjet printed electronics: a potential route to parts with embedded multifunctionality

“…Another possibility is to reduce the time taken for each layer to be fabricated, which is most readily achievable by using an area-based energy exposure, rather than scanning of a point energy source. Two such methods that have demonstrated area-based exposure are High Speed Sintering, which uses an infra red lamp and a patterned infra red absorber to selectively fuse together polymer powder [16]; and area based stereolithography, which utilises a UV emitting lamp in conjunction with a digital micromirror device as used in most modern projectors. One of the most developed of the area-based stereolithography techniques is Continuous Liquid Interface Production [17].…”

“…This capability has previously been exploited within additive manufacturing, either by the direct printing of a three dimensional object [27,28], printing of a binder material into a bed of powder [29,30], or the printing of selective sensitiser onto a powder bed subjected to further processing [16]. In addition to these uses in additive manufacturing, inkjet printing has also been used in areas as diverse as tissue engineering [31], biosensor fabrication [32], aerospace composites [33] and printed electronics [34].…”