Residual Stress Generation during Laser Cladding of Steel with a Particulate Metal Matrix Composite

Abstract

Laser cladding is used to coat and repair the surface of various components. A significant issue relating to optimisation of the process is the generation of residual stresses. These are affected by the high thermal gradients inherent in the process, and associated differential thermal contraction. These stresses can lead to various types of distortion. A customised 3‐D finite element model has been developed, incorporating these effects, based on simulation of conductive, convective and radiative heat transfer, and assuming elastic‐perfectly plastic deformation behaviour. Creep effects have been neglected and the cladding (particulate metal matrix composite) has been treated as a continuum. Comparisons are presented between measured and simulated thermal fields and specimen deflection histories. The results indicate that the main features of residual stress generation in this type of system have been captured in the model. Implications for process optimization and control are briefly discussed.

Measurement of the Debonding Resistance of Strongly Adherent Thick Coatings on Metals via In‐plane Tensile Straining

“…[26] As a result of the complex strain/temperature history experienced during the coating process, coatings made by laser cladding present residual stresses, r res . [25] X ray diffraction measurements carried out on similar coatings showed compressive normal stresses r res ≈ 35 MPa in the Ni matrix. [9] Figure 1 presents the dimensions of the dog bone shaped tensile specimens that have been machined from the coated plates by spark erosion.…”

Experimental Study on Surface Characteristics of Laser Cladding Layer Regulated by High-Frequency Microforging

“…According to the parameters (density and acoustic velocity) of Ni-base alloy coating and substrate of steel 20 (C 0. 17 Journal of Thermal Spray Technology microforging process. The compressive stress on the whole cladding layer is remarkably stronger than that in the substrate.…”

“…According to overall literature (Ref [15][16][17][18][19][20][21], one of the important causes of the generation of cracks is the strong residual tensile stress experienced while the laser cladding layer is in an as-cast state, and there are many internal microcracks, which are not tough enough to endure great tensile stress. Literature (Ref 22,23) pointed out that microcracking in the parts is one of the urgent problems to be solved in laser cladding forming technology.…”

“…In recent years, the residual stress in surface engineering aroused the attention of many scholars; the latest research (Ref [15][16][17][18][19][20][21] showed that the regulation of residual stress state of the coating surface could improve the coating characteristics greatly (including the cracking behavior, bond strength, and wear characteristics, etc.). Mainly, there are two methods of regulating residual surface stress, namely, to optimize parameters of coating preparation or to introduce an external energy into the coating.…”

Recent Advances In Metal Manufacturing Techniques Used In Prosthetic Dentistry

“…Bu teknikte, kaplama materyali ile substrat arasındaki bağlantının dayanıklı olması amacıyla, substrat yüzeyinde çok ince bir tabaka eritilmektedir. 40 Bu işlem aynı zamanda, lazer ile tasarlanmış ağ şekillendirme (LENS) olarak da adlandırılmaktadır. Metal alt yapı üretim teknolojilerinin kullanım alanları: Sabit protetik restorasyonların üretiminde kullanımı Hızlı üretim teknikleri; ana parçadan malzeme uzaklaştırmak yerine, malzemeyi yığarak üretim yapma özelliği ile günümüz CAD/CAM sistemlerine kıyasla maliyetten büyük ölçüde tasarruf sağlamaktadır.…”