scholarly journals Effect of Laser Rescanning on the Characteristics and Residual Stress of Selective Laser Melted Titanium Ti6Al4V Alloy

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 3940 ◽  
Author(s):  
Xiaojin Miao ◽  
Meiping Wu ◽  
Jitai Han ◽  
Haohao Li ◽  
Xiu Ye
Keyword(s):  
Residual Stress ◽  
Ti6al4v Alloy ◽  
High Tech ◽  
Complex Structures ◽  
Laser Melting ◽  
Average Residual ◽  
Metal Materials ◽  
Scanning Strategies ◽  
Ideal Process

The titanium Ti6Al4V alloy has excellent properties, and is one of the most important and widely used metal materials in the field of modern high-tech. Selective laser melting (SLM) is an ideal process for the rapid prototyping of Ti6Al4V alloy components with complex structures, but the performances need to be further improved. In this paper, the relative density, hardness, and microstructure under different scanning conditions were first analyzed in order to clarify the role of rescanning process in improving the performances. Then, the effects of different scanning strategies on the residual stress were analyzed. The results show that the strategy of partition rescanning has the most significant effect on residual stress. Finally, the SLM experiments of aviation nozzle rings were carried out. The results show that the average residual stress of the Re-SLMed sample was reduced from 322 MPa to 254 MPa.

scholarly journals The Effect of a Scanning Strategy on the Residual Stress of 316L Steel Parts Fabricated by Selective Laser Melting (SLM)

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1821 ◽  
Author(s):  
Di Wang ◽  
Shibiao Wu ◽  
Yongqiang Yang ◽  
Wenhao Dou ◽  
Shishi Deng ◽  
...  
Keyword(s):  
Residual Stress ◽  
Selective Laser Melting ◽  
Laser Scanning ◽  
Effective Means ◽  
Laser Melting ◽  
Scanning Strategy ◽  
Deformation Degree ◽  
316L Steel ◽  
Stress And Deformation ◽  
Scanning Strategies

The laser scanning strategy has an important influence on the surface quality, residual stress, and deformation of the molten metal (deformation behavior). A divisional scanning strategy is an effective means used to reduce the internal stress of the selective laser melting (SLM) metal part. In order to understand and optimize the divisional scanning strategy, three divisional scanning strategies and an S-shaped orthogonal scanning strategy are used to produce 316L steel parts in this study. The influence of scanning strategy on the produced parts is verified from the aspects of densification, residual stress distribution and deformation. Experiments show that the 316L steel alloy parts adopted spiral divisional scanning strategy can not only obtain the densification of 99.37%, but they also effectively improve the distribution of residual stress and control the deformation degree of the produced parts. Among them, the spiral divisional scanning sample has the smallest residual stress in plane direction, and its σx and σy stress are controlled within 204 MPa and 103 MPa. The above results show that the spiral divisional scanning is the most conducive strategy to obtain higher residual stress performance of SLM 316L steel parts.

Determination of residual stress for Inconel 718 samples fabricated through different scanning strategies in selective laser melting

2020 ◽  
Author(s):  
Vignesh Ram Kumar Rajendran ◽  
Kiriti Mamidi ◽  
Bharath Ravichander ◽  
Behzad Farhang ◽  
Amirhesam Amerinatanzi ◽  
...  
Keyword(s):  
Residual Stress ◽  
Selective Laser Melting ◽  
Inconel 718 ◽  
Laser Melting ◽  
Scanning Strategies

The effect of hatch angle rotation on parts manufactured using selective laser melting

2019 ◽  
Vol 25 (2) ◽  
pp. 289-298 ◽  
Author(s):  
Joseph Henry Robinson ◽  
Ian Robert Thomas Ashton ◽  
Eric Jones ◽  
Peter Fox ◽  
Chris Sutcliffe
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Selective Laser Melting ◽  
Pure Titanium ◽  
Commercially Pure Titanium ◽  
Laser Melting ◽  
Content Type ◽  
Axial Tensile ◽  
Effects Of Rotation ◽  
Scanning Strategies

Purpose This paper aims to present an investigation into the variation of scan vector hatch rotation strategies in selective laser melting (SLM), focussing on how it effects density, surface roughness, tensile strength and residual stress. Design/methodology/approach First the optimum angle of hatch vector rotation is proposed by analysing the effect of different increment angles on distribution of scan vectors. Sectioning methods are then used to determine the effect that the chosen strategies have on the density of the parts. The top surface roughness was analysed using optical metrology, and the tensile properties were determined using uni-axial tensile testing. Finally, a novel multi-support deflection geometry was used to quantify the effects of rotation angles on residual stress. Findings The results of this research showed that the hatch rotation angle had little effect on the density, top surface roughness and strength of the parts. The greatest residual stress deflection was measured parallel to unidirectional scan vectors. The use of hatch rotations other than alternating 90° showed little benefit in lowering the magnitude of residual stresses. However, the use of rotation angles with a good suitability measure distributes stresses in all directions more evenly for certain part geometries. Research limitations/implications All samples produced in this work were made from commercially pure titanium, therefore care must be taken when applying these results to other materials. Originality/value This paper serves to increase the understanding of SLM scanning strategies and their effect on the properties of the material.

scholarly journals Cracking Behavior of René 104 Nickel-Based Superalloy Prepared by Selective Laser Melting Using Different Scanning Strategies

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2149
Author(s):  
Kai Peng ◽  
Ranxi Duan ◽  
Zuming Liu ◽  
Xueqian Lv ◽  
Quan Li ◽  
...  
Keyword(s):  
Residual Stress ◽  
Relative Density ◽  
Selective Laser Melting ◽  
Laser Melting ◽  
High Quality ◽  
Cracking Behavior ◽  
Nickel Based Superalloy ◽  
Size Number ◽  
Cracking Performance ◽  
Scanning Strategies

Eliminating cracks is a big challenge for the selective laser melting (SLM) process of low-weldable Nickel-based superalloy. In this work, three scanning strategies of the snake, stripe partition, and chessboard partition were utilized to prepare René 104 Ni-based superalloy, of which the cracking behavior and the residual stress were investigated. The results showed that the scanning strategies had significant effects on the cracking, residual stress, and relative density of the SLMed René 104 superalloy. The scanning strategies with more partitions boosted the emergence of cracks, as high-density cracks occurred in these samples. The overlapping zone (OZ) of the scanning partition was also susceptible to cracking, which increased the size, number, and density of the cracks. The cracking performance was relatively moderate in the snake-scanned samples, while that in the chessboard-partition-scanned samples was the most severe. It is concluded that the partition scanning strategies induced more cracks in the SLMed René 104 superalloy, of which the residual stress was apparently reduced. Therefore, it is necessary to design scanning strategies with optimized scanning partitions and overlaps to avoid cracking and acquire a high-quality, near fully dense, low-weldable Nickel-based superalloy using SLM.

Role of scanning strategy on residual stress distribution in Ti-6Al-4V alloy prepared by selective laser melting

Optik ◽  
2018 ◽  
Vol 170 ◽  
pp. 342-352 ◽  
Author(s):  
Jia Song ◽  
Wenheng Wu ◽  
Liang Zhang ◽  
Beibei He ◽  
Lin Lu ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Selective Laser Melting ◽  
Residual Stress Distribution ◽  
Laser Melting ◽  
Scanning Strategy

The Indices of Creative Cities: the Global and Local Aspects

2015 ◽  
Vol 4 (1) ◽  
pp. 95 ◽  
Author(s):  
Tomas Kačerauskas
Keyword(s):  
High Tech ◽  
Melting Pot ◽  
Creative Cities ◽  
Global And Local

The paper deals with the indices of creative cities. Author analyses the different creativity indices suggested by both the followers and the critics of R. Florida. The author criticizes the Florida’s indices such as Bohemian, Melting pot, Gay, High tech, Innovation, Talent indices, as well as Minor integrative (diversity) and Major integrative indices. The indices of other authors presuppose the questions about the role of the region in defining certain creativity indices. The author makes conclusion that the uniform formula of creativity indices is impossible for two reasons. First, the creativity indices depend on the region of a city. Second, the very strategy to have the uniform creativity indices makes the cities similar to each other and no more unique, consequently, no more creative; as result, this strategy is anti-creative.

Sign in / Sign up

Export Citation Format

Share Document