In:
Materials Testing, Walter de Gruyter GmbH, Vol. 61, No. 2 ( 2019-02-04), p. 125-130
Abstract:
Pre-cracked 304 stainless steel compact tension specimens were repaired by a CO 2 laser at the crack tips with the addition of different weight fractions of nano-Al 2 O 3 . Crack opening displacements were measured by a digital image correlation system for the evaluation of fracture performance. Microstructures of the repaired areas were examined by scanning electron microscopy equipped with an energy dispersive spectrometer. Results indicated that laser repair with the addition of 1.0 wt.-% nano-Al 2 O 3 resulted in metallurgical bonding at the interface and fine columnar crystal in the repair layer. The addition of nano-Al 2 O 3 increases sites of heterogeneous nucleation, which acts as a fine-grain strengthener. In addition, the uniform distribution of nano-Al 2 O 3 plays a role in dispersion strengthening, resulting in improved fracture performance by approximately 10 % to 30 % as applied loads varied from 1 to 20 kN. However, the excessive addition of nano-Al 2 O 3 gives rise to the agglomeration and micro-cracks in the repair layers and clear detachment are observed at the interface.
Type of Medium:
Online Resource
ISSN:
2195-8572
,
0025-5300
Language:
English
Publisher:
Walter de Gruyter GmbH
Publication Date:
2019
detail.hit.zdb_id:
2280363-4
detail.hit.zdb_id:
206395-5
Permalink