Pencirian dan perbandingan serbuk aloi titanium (Ti6Al4V) yang digunakan dalam Peleburan Laser Selektif (SLM)

Ciri serbuk aloi titanium (Ti6Al4V) yang digunakan dalam pembuatan aditif logam (MAM) amat penting dalam menjamin mutu produk yang dihasilkan. Salah satu teknologi dalam MAM adalah Peleburan Laser Selektif (SLM). Mesin pencetakan SLM telah dibangunkan oleh beberapa syarikat seperti SLM Solutions Group AG dan Renishaw PLC. Bagi menjamin kualiti produk mesin masing-masing, setiap syarikat menghasilkan serbuk logam tersendiri. Hal ini membataskan potensi penggunaan SLM kerana pengguna tidak boleh menggunakan serbuk logam mereka sendiri. Maka, kajian ini bertujuan untuk mengkaji perbezaan antara serbuk Ti6Al4V yang dihasilkan oleh SLM Solutions dan Renishaw, dan juga menentukan ciri serbuk Ti6Al4V yang sesuai untuk kaedah SLM. Pencirian sampel serbuk telah dilakukan bagi mengkaji bentuk dan saiz zarah, rencaman kimia dan struktur kristalografi. Sampel serbuk Ti6Al4V daripada SLM Solutions dan Renishaw masing-masing ditandakan sebagai S1 dan S2. Analisis SEM menunjukkan sampel S2 mempunyai bentuk sfera yang lebih sempurna berbanding sampel S1. Analisis rencaman kimia menunjukkan kedua-dua sampel mempunyai taburan unsur kimia yang serupa dengan nilai kajian lampau. Selain itu, analisis taburan saiz zarah menunjukkan saiz zarah S1 dan S2 adalah kurang daripada 45 μm dengan nilai tersebut masih dalam lingkungan yang boleh diterima dalam MAM iaitu 10 hingga 60 μm. Analisis XRD menunjukkan kedua-dua sampel mempunyai puncak keamatan dan struktur kristal berbentuk heksagon yang serupa. Diharapkan makalah ini dapat dijadikan panduan bagi mereka yang ingin menghasilkan sendiri serbuk Ti6Al4V bagi penggunaan proses fabrikasi SLM

Review on volumetric energy density: inluence on morphology and mechanical properties of Ti6Al4V manufactured via laser powder bed fusion

Various laser powder bed fusion (LPBF) process parameters must be considered as they can independently affect the properties of end-product. However, many studies simply examine one or two LPBF process parameters. Laser power, scan speed, scan spacing, and layer height are the four primary LPBF process parameters that contribute to volumetric energy density (VED) used in LPBF. VED is often used as an optimization metric for LPBF process parameters, because it takes all four major parameters into consideration. Thus, this paper focuses on the effect of VED on the morphology and properties of part, and also discusses on the interrelationship between all four parameters. Common range used for each parameter is 70–400 W for laser power, 70–1800 mm/s for scan speed, 50–140 µm for scan spacing, and 20–50 µm for layer height. It can be seen as the VED increased, the microstructure of as-built titanium alloy Ti6Al4V components exhibited smaller α’ martensite size and larger columnar β grain. High VED can also reduce porosity and defect formation, which will help in increasing part density. The lowest surface roughness reported for LPBF Ti6Al4V is 4.91 µm. Meanwhile, the maximum microhardness obtained is 443 HV and the highest tensile strength achieved is 1400 MPa. The VED used for studies that obtained these results are in the range of 55–65 J/mm3. Thus, it can be concluded that the most suitable VED for LPBF printing of Ti6Al4V is around 55–65 J/mm3

Review on volumetric energy density: Influence on morphology and mechanical properties of Ti6Al4V manufactured via laser powder bed fusion

Various laser powder bed fusion (LPBF) process parameters must be considered as they can independently affect the properties of end-product. However, many studies simply examine one or two LPBF process parameters. Laser power, scan speed, scan spacing, and layer height are the four primary LPBF process parameters that contribute to volumetric energy density (VED) used in LPBF. VED is often used as an optimization metric for LPBF process parameters, because it takes all four major parameters into consideration. Thus, this paper focuses on the effect of VED on the morphology and properties of part, and also discusses on the interrelationship between all four parameters. Common range used for each parameter is 70–400 W for laser power, 70–1800 mm/s for scan speed, 50–140 µm for scan spacing, and 20–50 µm for layer height. It can be seen as the VED increased, the microstructure of as-built titanium alloy Ti6Al4V components exhibited smaller α’ martensite size and larger columnar β grain. High VED can also reduce porosity and defect formation, which will help in increasing part density. The lowest surface roughness reported for LPBF Ti6Al4V is 4.91 µm. Meanwhile, the maximum microhardness obtained is 443 HV and the highest tensile strength achieved is 1400 MPa. The VED used for studies that obtained these results are in the range of 55–65 J/mm3. Thus, it can be concluded that the most suitable VED for LPBF printing of Ti6Al4V is around 55–65 J/mm3