Non-Contact Multiscale Analysis of a DPP 3D-Printed Injection Die for Investment Casting

Direct metal printing is a promising technique for manufacturing injection molds with complex conformal cooling channels from maraging steel powder, which is widely applied in automotive or aerospace industries. However, two major disadvantages of direct metal printing are the narrow process window and length of time consumed. The fabrication of high-density injection molds is frequently applied to prevent coolant leakage during the cooling stage. In this study, we propose a simple method of reducing coolant leakage for a direct-metal-printed injection mold with conformal cooling channels by combining injection mold fabrication with general process parameters, as well as solution and aging treatment (SAT). This study comprehensively investigates the microstructural evolution of the injection mold after SAT using field-emission scanning electron microscopy and energy-dispersive X-ray spectroscopy. We found that the surface hardness of the injection mold was enhanced from HV 189 to HV 546 as the Ni-Mo precipitates increased from 12.8 to 18.5%. The size of the pores was reduced significantly due to iron oxide precipitates because the relative density of the injection mold increased from 99.18 to 99.72%. The total production time of the wax injection mold without coolant leakage during the cooling stage was only 62% that of the production time of the wax injection mold fabricated with high-density process parameters. A significant savings of up to 46% of the production cost of the injection mold was obtained.

Section: Resultsmentioning

confidence: 86%

A Simple Method of Reducing Coolant Leakage for Direct Metal Printed Injection Mold with Conformal Cooling Channels Using General Process Parameters and Heat Treatment

Kuo

Qiu

2021

“…After visually analyzing them, to investigate the impact of the innovative method for removing excess material from welds in specimens made of various stainless steels and aluminum alloys on the key parameters of the surface geometric structures [33,34], surface roughness measurements were conducted using a non-contact optical method extensively described in the modern scientific literature [35,36]. This method facilitates an accurate and a high-quality removal of weld beads [5].…”

Section: Methodsmentioning

confidence: 99%

“…After visually analyzing them, to investigate the impact of the innovative method for removing excess material from welds in specimens made of various stainless steels and aluminum alloys on the key parameters of the surface geometric structures [33,34], surface roughness measurements were conducted using a non-contact optical method extensively described in the modern scientific literature [35,36]. To visually analyze the obtained surface and identify areas of characteristic roughness, images were captured at a magnification of 32 times using a SmartZoom 5 digital industrial microscope by Zeiss (Carl Zeiss AG, Oberkochen, Germany) [5].…”

Section: Methodsmentioning

confidence: 99%

Exploring the Potential Application of an Innovative Post-Weld Finishing Method in Butt-Welded Joints of Stainless Steels and Aluminum Alloys

Łastowska,

Starosta,

Jabłońska

et al. 2024

The prerequisite of the weld bead finishing is intricately linked to the quality of the welded joint. It constitutes the final, yet pivotal, stage in its formation, significantly influencing the reliability of structural components and machines. This article delineates an innovative post-weld surface finishing method, distinguished by the movement of a specialized cutting tool along a butt weld. This method stands out due to its singular approach to machining allowance, wherein the weld bead height is considered and eradicated in a single pass of the cutting tool. Test samples were made of AISI 304L, AISI 316L stainless steels and EN AW-5058 H321, EN AW-7075 T651 aluminum alloys butt-welded with TIG methods. Following the welding process, the weld bead was finished in accordance with the innovative method to flush the bead and the base metal’s surface. For the quality control of welded joints before and after the weld finishing, two non-destructive testing methods were chosen: Penetrant Testing (PT) and Radiographic Testing (RT). This article provides results from the examination of 2D profile parameters and 3D stereometric characteristics of surface roughness using the optical method. Additionally, metallographic results are presented to assess changes in the microstructure, the microhardness, and the degree of hardening within the surface layer induced by the application of the innovative post-weld finishing method.

“…The second group of measurement methods are non-contact methods, in which there is no contact between the measuring instrument and the object being measured [26,27]. This allows for accurate measurements of objects with complex shapes, of both small and large size [28][29][30][31], as well as those made of flexible materials such as sponges, foams, or plastics [32,33] or made by additive technologies [34][35][36]; the same applies to metal elements manufactured by wire arc additive manufacturing [37]. For such large components as the welded frame under study, the use of a photogrammetric method is both reasonable and preferable.…”

Section: Introductionmentioning

confidence: 99%

Experimental Verification of Geometric Changes Caused by the Release of Residual Stresses for Large-Scale Welded Frames

Wieczorowski,

Jakubowicz,

Marciniak-Podsadna

et al. 2024

Self Cite

This paper presents geometric analyses of welded frames after free relaxing and vibratory stress relief (VSR). The tested frames were components of a prototype packaging machine. Two types of relaxation were carried out to remove stresses introduced as a result of the welding process. One of the frames was subjected to free relaxation, while the other one was subjected to accelerated vibration relaxation. Detection of the frame geometry changes was performed using a photogrammetric system. In addition, an evaluation of the geometry change was conducted for fifteen variants of a steel frame support. A comparative analysis of the geometric deviations of the frames after free and vibratory stress relief confirmed the assumption that the frame post vibration stress relief better reproduces the nominal dimensions. Nevertheless, it should be emphasized that after vibratory stress relief, the frame is not subject to further deformation, which is a desirable effect. In the case of free relaxing, the frame undergoes dimensional changes in a random manner. In summary, carrying out accelerated vibratory stress relief allows for control of spontaneous dimensional changes in the designed frame of a packaging machine resulting from spontaneous relaxation of stresses arising from the welding process. The shortening of the relaxation process of the welded frame is also an unquestionable advantage.