The direct metal deposition of H13 tool steel for 3-D components

Freeform Laser Consolidated H13 and CPM 9V Tool Steels

“…Repeatedly, the prior deposited layers went through multiple thermal cycles, which finally tempered the major portion of the LC steels except the top several deposited layers of the thin wall. This is exactly the case for the LC H13 steel, which also agreed with the observation on the LENS-and DMDproduced H13 steels [9,13,17,29,30]. Comparatively, the LC CPM 9V steel acted slightly differently, the microstructure in the slightly ''dark'' region at the top of each deposited layer, which was thermally affected by the immediate deposition of the subsequent layer, exhibits partially dissolved eutectic phase at the inter-cellular regions due to re-austenitization during re-heating, but less affected by thermal-cycle-induced tempering.…”

“…To that end, laser-cladding-based freeform fabrication [4,5], which could directly fabricate functional shapes (features or structures) without molds and dies, presents a high potential on manufacturing of TDM; representative technologies of such kind include laser engineered net shaping (LENS TM ) [6,7], direct light fabrication (DLF) [8], direct metal deposition (DMD) [9,10], laser direct casting (LDC) [11], and others which have been well documented [4,5]. A lot of investigations have been reported to promote these processes for TDM materials development and rapid manufacturing by direct fabricating functional shapes or by enhancing, repairing, or re-configuring existing TDM with affordable cost [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23].…”

“…A lot of investigations have been reported to promote these processes for TDM materials development and rapid manufacturing by direct fabricating functional shapes or by enhancing, repairing, or re-configuring existing TDM with affordable cost [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]. However, it is also realized that some of these processes might only produce a ''near-net'' shape with rough surface finish and low-dimensional accuracy [4,5,22,23] and, thus, post-machining is a must, which, more or less, could diminish the attractiveness of the processes.…”

“…H13 tool steel has already been widely investigated by LENS and DMD processes [9,13,17,29,30]. In contrast, CPM 9V steel belongs to a family of novel CPM tool steels, which possess substantially improved abrasive wear resistance in combination with enhanced toughness and heat check resistance due to the presence of a high amount of primary vanadium carbides in the matrix [28].…”

Hybrid Manufacturing System Design and Development

“…In general, decreasing process speed increases the layer thickness. There is a threshold to reduce process speed, however, as too much specific energy (as defined in Section 5.2.2) will cause tempering or secondary hardening of previous layers (Mazumder et al, 1997). Process speed should be well chosen since it has strong influence on microstructure.…”