Model
export interface IPoducts{
     recordname: string;
     comments: [{
         comment: string
      }]
}

constructor(public dialog: MdDialog, private productService: ProductService){}
prod: IProducts[]=[]
ngOnInit(): void{         this.productService.getProcessnotes().subscribe(producsts=>this.products=products,error=>this.errorMessage=<any>error);

 //opening dialgue
openDialog(prod:any): void {
    let dialogRef = this.dialog.open(prodDialog, {
      width: '400px',
      height: '500px;',
    data: this.prod  <------------------passing the object array
      });
  }}

export class ProdDialog implements OnInit{
       public pnote: IProducts[];
      constructor(
        public dialogRef: MdDialogRef<DialogOverviewExampleDialog>,
    @Inject(MD_DIALOG_DATA) public  data: {pnote:this.prod }) { }
     public pnote: products;
      onNoClick(): void {
        this.dialogRef.close();
      }
       public ngOnInit():void{
           this.pnote=this.data.prod;

       }

In main template button triggers the dialog box by passing a pnote from *ngFor="let pnote of products"

 <button md-raised-button (click)="openDialog(pnote)">Open Dialog</button>

<div>
  <h2 md-dialog-title>MY DIALOG</h2>
  <hr>
  <md-dialog-content>
        <div*ngFor=prod in products>
          {{prod.recorname}}
        </div>
    <br>
    <br>
    <strong>{{data}}</strong>
  </md-dialog-content>
  <hr>
  <md-dialog-actions>
    <button md-raised-button (click)="onCloseConfirm()">CONFIRM</button>&nbsp;
    <button md-raised-button (click)="onCloseCancel()">CANCEL</button>
  </md-dialog-actions>
</div>